diff --git a/src/main/c/build/linux-x86_64.sh b/src/main/c/build/linux-x86_64.sh
index 9d14f94..9d25cb8 100755
--- a/src/main/c/build/linux-x86_64.sh
+++ b/src/main/c/build/linux-x86_64.sh
@@ -9,8 +9,9 @@ set -e
 OS="linux"
 ARCH="x86_64"
 HOST="$ARCH-$OS-gnu"
-CFLAGS="-m64"
+CFLAGS="-m64 -Wl,--wrap=memcpy"
 LIBUSB_CONFIG="--disable-shared --disable-udev"
 USB4JAVA_LIBS="-lrt"
+USB4JAVA_CFLAGS="-DWRAP_MEMCPY"
 
 build
diff --git a/src/main/c/src/BosDescriptor.c b/src/main/c/src/BosDescriptor.c
index 12aadc5..4a65a2d 100644
--- a/src/main/c/src/BosDescriptor.c
+++ b/src/main/c/src/BosDescriptor.c
@@ -7,7 +7,7 @@
 #include "BosDevCapabilityDescriptor.h"
 
 void setBosDescriptor(JNIEnv* env,
-    struct libusb_bos_descriptor* descriptor, jobject object)
+    const struct libusb_bos_descriptor* descriptor, jobject object)
 {
     SET_POINTER(env, descriptor, object, "bosDescriptorPointer");
 }
@@ -35,7 +35,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(BosDescriptor, bLength)
     struct libusb_bos_descriptor *descriptor =
         unwrapBosDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bLength;
+    return (jbyte) descriptor->bLength;
 }
 
 /**
@@ -49,7 +49,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(BosDescriptor, bDescriptorType)
     struct libusb_bos_descriptor *descriptor =
         unwrapBosDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bDescriptorType;
+    return (jbyte) descriptor->bDescriptorType;
 }
 
 /**
@@ -63,7 +63,7 @@ JNIEXPORT jshort JNICALL METHOD_NAME(BosDescriptor, wTotalLength)
     struct libusb_bos_descriptor *descriptor =
         unwrapBosDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->wTotalLength;
+    return (jshort) descriptor->wTotalLength;
 }
 
 /**
@@ -77,7 +77,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(BosDescriptor, bNumDeviceCaps)
     struct libusb_bos_descriptor *descriptor =
         unwrapBosDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bNumDeviceCaps;
+    return (jbyte) descriptor->bNumDeviceCaps;
 }
 
 /**
diff --git a/src/main/c/src/BosDescriptor.h b/src/main/c/src/BosDescriptor.h
index c7e0fd4..13166eb 100644
--- a/src/main/c/src/BosDescriptor.h
+++ b/src/main/c/src/BosDescriptor.h
@@ -8,7 +8,7 @@
 
 #include "usb4java.h"
 
-void setBosDescriptor(JNIEnv*, struct libusb_bos_descriptor*, jobject);
+void setBosDescriptor(JNIEnv*, const struct libusb_bos_descriptor*, jobject);
 struct libusb_bos_descriptor* unwrapBosDescriptor(JNIEnv*, jobject);
 void resetBosDescriptor(JNIEnv*, jobject);
 
diff --git a/src/main/c/src/BosDevCapabilityDescriptor.c b/src/main/c/src/BosDevCapabilityDescriptor.c
index eed2fb9..6bf0cc6 100644
--- a/src/main/c/src/BosDevCapabilityDescriptor.c
+++ b/src/main/c/src/BosDevCapabilityDescriptor.c
@@ -13,21 +13,21 @@ jobject wrapBosDevCapabilityDescriptor(JNIEnv *env,
 }
 
 jobjectArray wrapBosDevCapabilityDescriptors(JNIEnv *env, int count,
-    struct libusb_bos_dev_capability_descriptor **descriptors)
+    struct libusb_bos_dev_capability_descriptor * const *descriptors)
 {
-    int i;
-
     jobjectArray array = (jobjectArray) (*env)->NewObjectArray(env,
         count, (*env)->FindClass(env, PACKAGE_DIR"/BosDevCapabilityDescriptor"),
         NULL);
-    for (i = 0; i < count; i++)
+
+    for (int i = 0; i < count; i++)
         (*env)->SetObjectArrayElement(env, array, i,
             wrapBosDevCapabilityDescriptor(env, descriptors[i]));
+
     return array;
 }
 
-struct libusb_bos_dev_capability_descriptor
-    *unwrapBosDevCapabilityDescriptor(JNIEnv *env, jobject obj)
+struct libusb_bos_dev_capability_descriptor*
+    unwrapBosDevCapabilityDescriptor(JNIEnv *env, jobject obj)
 {
     UNWRAP_POINTER(env, obj, struct libusb_bos_dev_capability_descriptor*,
         "bosDevCapabilityDescriptorPointer");
@@ -44,7 +44,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(BosDevCapabilityDescriptor, bLength)
     struct libusb_bos_dev_capability_descriptor* descriptor =
         unwrapBosDevCapabilityDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bLength;
+    return (jbyte) descriptor->bLength;
 }
 
 /**
@@ -59,7 +59,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(BosDevCapabilityDescriptor,
     struct libusb_bos_dev_capability_descriptor* descriptor =
         unwrapBosDevCapabilityDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bDescriptorType;
+    return (jbyte) descriptor->bDescriptorType;
 }
 
 /**
@@ -74,7 +74,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(BosDevCapabilityDescriptor,
     struct libusb_bos_dev_capability_descriptor* descriptor =
         unwrapBosDevCapabilityDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bDevCapabilityType;
+    return (jbyte) descriptor->bDevCapabilityType;
 }
 
 /**
@@ -89,6 +89,5 @@ JNIEXPORT jobject JNICALL METHOD_NAME(BosDevCapabilityDescriptor,
     struct libusb_bos_dev_capability_descriptor *descriptor =
         unwrapBosDevCapabilityDescriptor(env, this);
     if (!descriptor) return NULL;
-    return (*env)->NewDirectByteBuffer(env, (void *)
-        descriptor->dev_capability_data, descriptor->bLength - 3);
+    return NewDirectReadOnlyByteBuffer(env, descriptor->dev_capability_data, descriptor->bLength - 3);
 }
diff --git a/src/main/c/src/BosDevCapabilityDescriptor.h b/src/main/c/src/BosDevCapabilityDescriptor.h
index 82d553c..2cd376c 100644
--- a/src/main/c/src/BosDevCapabilityDescriptor.h
+++ b/src/main/c/src/BosDevCapabilityDescriptor.h
@@ -8,9 +8,11 @@
 
 #include "usb4java.h"
 
+jobject wrapBosDevCapabilityDescriptor(JNIEnv *,
+    const struct libusb_bos_dev_capability_descriptor *);
 jobjectArray wrapBosDevCapabilityDescriptors(JNIEnv*, int,
-    struct libusb_bos_dev_capability_descriptor**);
-struct libusb_bos_dev_capability_descriptor
-    *unwrapBosDevCapabilityDescriptor(JNIEnv *, jobject);
+    struct libusb_bos_dev_capability_descriptor * const *);
+struct libusb_bos_dev_capability_descriptor*
+    unwrapBosDevCapabilityDescriptor(JNIEnv *, jobject);
 
 #endif
diff --git a/src/main/c/src/ContainerIdDescriptor.c b/src/main/c/src/ContainerIdDescriptor.c
index e40e65e..d72625b 100644
--- a/src/main/c/src/ContainerIdDescriptor.c
+++ b/src/main/c/src/ContainerIdDescriptor.c
@@ -6,7 +6,7 @@
 #include "ContainerIdDescriptor.h"
 
 void setContainerIdDescriptor(JNIEnv* env,
-    struct libusb_container_id_descriptor* descriptor, jobject object)
+    const struct libusb_container_id_descriptor* descriptor, jobject object)
 {
     SET_POINTER(env, descriptor, object, "containerIdDescriptorPointer");
 }
@@ -35,7 +35,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(ContainerIdDescriptor, bLength)
     struct libusb_container_id_descriptor *descriptor =
         unwrapContainerIdDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bLength;
+    return (jbyte) descriptor->bLength;
 }
 
 /**
@@ -49,7 +49,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(ContainerIdDescriptor, bDescriptorType)
     struct libusb_container_id_descriptor *descriptor =
         unwrapContainerIdDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bDescriptorType;
+    return (jbyte) descriptor->bDescriptorType;
 }
 
 /**
@@ -63,7 +63,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(ContainerIdDescriptor, bDevCapabilityType)
     struct libusb_container_id_descriptor *descriptor =
         unwrapContainerIdDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bDevCapabilityType;
+    return (jbyte) descriptor->bDevCapabilityType;
 }
 
 /**
@@ -77,7 +77,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(ContainerIdDescriptor, bReserved)
     struct libusb_container_id_descriptor *descriptor =
         unwrapContainerIdDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bReserved;
+    return (jbyte) descriptor->bReserved;
 }
 
 /**
@@ -91,6 +91,5 @@ JNIEXPORT jobject JNICALL METHOD_NAME(ContainerIdDescriptor, containerId)
     struct libusb_container_id_descriptor *descriptor =
         unwrapContainerIdDescriptor(env, this);
     if (!descriptor) return NULL;
-    return (*env)->NewDirectByteBuffer(env, (void *) descriptor->ContainerID,
-        16);
+    return NewDirectReadOnlyByteBuffer(env, descriptor->ContainerID, 16);
 }
diff --git a/src/main/c/src/ContainerIdDescriptor.h b/src/main/c/src/ContainerIdDescriptor.h
index 0114aa8..698c8c8 100644
--- a/src/main/c/src/ContainerIdDescriptor.h
+++ b/src/main/c/src/ContainerIdDescriptor.h
@@ -9,7 +9,7 @@
 #include "usb4java.h"
 
 void setContainerIdDescriptor(JNIEnv*,
-    struct libusb_container_id_descriptor*, jobject);
+    const struct libusb_container_id_descriptor*, jobject);
 struct libusb_container_id_descriptor*
     unwrapContainerIdDescriptor(JNIEnv*, jobject);
 void resetContainerIdDescriptor(JNIEnv*, jobject);
diff --git a/src/main/c/src/DeviceDescriptor.c b/src/main/c/src/DeviceDescriptor.c
index 3472897..7ecfbc6 100644
--- a/src/main/c/src/DeviceDescriptor.c
+++ b/src/main/c/src/DeviceDescriptor.c
@@ -11,10 +11,10 @@ void setDeviceDescriptor(JNIEnv* env,
     SET_POINTER(env, descriptor, object, "deviceDescriptorPointer");
 }
 
-struct libusb_device_descriptor* unwrapDeviceDescriptor(JNIEnv *env,
-    jobject obj)
+struct libusb_device_descriptor* unwrapDeviceDescriptor(JNIEnv* env,
+    jobject descriptor)
 {
-    UNWRAP_POINTER(env, obj, struct libusb_device_descriptor*,
+    UNWRAP_POINTER(env, descriptor, struct libusb_device_descriptor*,
         "deviceDescriptorPointer");
 }
 
diff --git a/src/main/c/src/DeviceHandle.c b/src/main/c/src/DeviceHandle.c
index 2d06da0..0f21888 100644
--- a/src/main/c/src/DeviceHandle.c
+++ b/src/main/c/src/DeviceHandle.c
@@ -18,8 +18,7 @@ jobject wrapDeviceHandle(JNIEnv* env, const libusb_device_handle* deviceHandle)
 
 libusb_device_handle* unwrapDeviceHandle(JNIEnv* env, jobject deviceHandle)
 {
-    UNWRAP_POINTER(env, deviceHandle, libusb_device_handle*,
-        "deviceHandlePointer");
+    UNWRAP_POINTER(env, deviceHandle, libusb_device_handle*, "deviceHandlePointer");
 }
 
 void resetDeviceHandle(JNIEnv* env, jobject object)
diff --git a/src/main/c/src/DeviceList.c b/src/main/c/src/DeviceList.c
index cdbfe56..292be4f 100644
--- a/src/main/c/src/DeviceList.c
+++ b/src/main/c/src/DeviceList.c
@@ -6,7 +6,7 @@
 #include "DeviceList.h"
 #include "Device.h"
 
-void setDeviceList(JNIEnv* env, libusb_device* const * list, jint size, jobject object)
+void setDeviceList(JNIEnv* env, libusb_device* const *list, jint size, jobject object)
 {
     SET_POINTER(env, list, object, "deviceListPointer");
 
@@ -38,7 +38,7 @@ JNIEXPORT jobject JNICALL METHOD_NAME(DeviceList, get)
     JNIEnv *env, jobject this, jint index
 )
 {
-    libusb_device **list = unwrapDeviceList(env, this);
+    libusb_device* const *list = unwrapDeviceList(env, this);
     if (!list) return NULL;
 
     jclass cls = (*env)->GetObjectClass(env, this);
diff --git a/src/main/c/src/LibUsb.c b/src/main/c/src/LibUsb.c
index 387b752..3a5f326 100644
--- a/src/main/c/src/LibUsb.c
+++ b/src/main/c/src/LibUsb.c
@@ -198,7 +198,7 @@ JNIEXPORT jint JNICALL METHOD_NAME(LibUsb, getPortNumbers)
     libusb_device *dev = unwrapDevice(env, device);
     if (!dev) return 0;
     jlong path_size = (*env)->GetDirectBufferCapacity(env, path);
-    return libusb_get_port_numbers(dev, path_ptr, path_size);
+    return libusb_get_port_numbers(dev, path_ptr, (int) path_size);
 }
 
 /**
@@ -254,7 +254,6 @@ JNIEXPORT jint JNICALL METHOD_NAME(LibUsb, getMaxPacketSize)
     NOT_NULL(env, device, return 0);
     libusb_device *dev = unwrapDevice(env, device);
     if (!dev) return 0;
-
     return libusb_get_max_packet_size(dev, (unsigned char) endpoint);
 }
 
@@ -269,7 +268,6 @@ JNIEXPORT jint JNICALL METHOD_NAME(LibUsb, getMaxIsoPacketSize)
     NOT_NULL(env, device, return 0);
     libusb_device *dev = unwrapDevice(env, device);
     if (!dev) return 0;
-
     return libusb_get_max_iso_packet_size(dev, (unsigned char) endpoint);
 }
 
@@ -284,7 +282,6 @@ JNIEXPORT jobject JNICALL METHOD_NAME(LibUsb, refDevice)
     NOT_NULL(env, device, return NULL);
     libusb_device *dev = unwrapDevice(env, device);
     if (!dev) return NULL;
-
     return wrapDevice(env, libusb_ref_device(dev));
 }
 
@@ -456,7 +453,6 @@ JNIEXPORT jint JNICALL METHOD_NAME(LibUsb, clearHalt)
     NOT_NULL(env, handle, return 0);
     libusb_device_handle *dev_handle = unwrapDeviceHandle(env, handle);
     if (!dev_handle) return 0;
-
     return libusb_clear_halt(dev_handle, (unsigned char) endpoint);
 }
 
@@ -624,6 +620,7 @@ JNIEXPORT jint JNICALL METHOD_NAME(LibUsb, getDeviceDescriptor)
     }
     else
     {
+        // Free memory again on error.
     	free(dev_desc);
     }
     return result;
@@ -761,7 +758,7 @@ JNIEXPORT jint JNICALL METHOD_NAME(LibUsb, getSsEndpointCompanionDescriptor)
     if (!ctx && context) return 0;
     NOT_NULL(env, endpointDescriptor, return 0);
     NOT_NULL(env, companionDescriptor, return 0);
-    NOT_SET(env, companionDescriptor, "ssEndpointCompanionDescriptor", return 0);
+    NOT_SET(env, companionDescriptor, "ssEndpointCompanionDescriptorPointer", return 0);
 
     struct libusb_endpoint_descriptor *endpoint_descriptor =
         unwrapEndpointDescriptor(env, endpointDescriptor);
diff --git a/src/main/c/src/SsEndpointCompanionDescriptor.c b/src/main/c/src/SsEndpointCompanionDescriptor.c
index eeb329c..3f39d8e 100644
--- a/src/main/c/src/SsEndpointCompanionDescriptor.c
+++ b/src/main/c/src/SsEndpointCompanionDescriptor.c
@@ -7,9 +7,9 @@
 #include "Interface.h"
 
 void setSsEndpointCompanionDescriptor(JNIEnv* env,
-    struct libusb_ss_endpoint_companion_descriptor* descriptor, jobject object)
+    const struct libusb_ss_endpoint_companion_descriptor* descriptor, jobject object)
 {
-    SET_POINTER(env, descriptor, object, "ssEndpointCompanionDescriptor");
+    SET_POINTER(env, descriptor, object, "ssEndpointCompanionDescriptorPointer");
 }
 
 struct libusb_ss_endpoint_companion_descriptor*
@@ -17,12 +17,12 @@ struct libusb_ss_endpoint_companion_descriptor*
 {
     UNWRAP_POINTER(env, descriptor,
         struct libusb_ss_endpoint_companion_descriptor*,
-        "ssEndpointCompanionDescriptor");
+        "ssEndpointCompanionDescriptorPointer");
 }
 
 void resetSsEndpointCompanionDescriptor(JNIEnv* env, jobject obj)
 {
-    RESET_POINTER(env, obj, "ssEndpointCompanionDescriptor");
+    RESET_POINTER(env, obj, "ssEndpointCompanionDescriptorPointer");
 }
 
 /**
@@ -36,7 +36,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(SsEndpointCompanionDescriptor, bLength)
     struct libusb_ss_endpoint_companion_descriptor *descriptor =
         unwrapSsEndpointCompanionDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bLength;
+    return (jbyte) descriptor->bLength;
 }
 
 /**
@@ -51,7 +51,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(SsEndpointCompanionDescriptor,
     struct libusb_ss_endpoint_companion_descriptor *descriptor =
         unwrapSsEndpointCompanionDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bDescriptorType;
+    return (jbyte) descriptor->bDescriptorType;
 }
 
 /**
@@ -65,7 +65,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(SsEndpointCompanionDescriptor, bMaxBurst)
     struct libusb_ss_endpoint_companion_descriptor *descriptor =
         unwrapSsEndpointCompanionDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bMaxBurst;
+    return (jbyte) descriptor->bMaxBurst;
 }
 
 /**
@@ -79,7 +79,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(SsEndpointCompanionDescriptor, bmAttributes)
     struct libusb_ss_endpoint_companion_descriptor *descriptor =
         unwrapSsEndpointCompanionDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bmAttributes;
+    return (jbyte) descriptor->bmAttributes;
 }
 
 /**
@@ -93,5 +93,5 @@ JNIEXPORT jshort JNICALL METHOD_NAME(SsEndpointCompanionDescriptor, wBytesPerInt
     struct libusb_ss_endpoint_companion_descriptor *descriptor =
         unwrapSsEndpointCompanionDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->wBytesPerInterval;
+    return (jshort) descriptor->wBytesPerInterval;
 }
diff --git a/src/main/c/src/SsEndpointCompanionDescriptor.h b/src/main/c/src/SsEndpointCompanionDescriptor.h
index e05d2be..3febd7d 100644
--- a/src/main/c/src/SsEndpointCompanionDescriptor.h
+++ b/src/main/c/src/SsEndpointCompanionDescriptor.h
@@ -9,7 +9,7 @@
 #include "usb4java.h"
 
 void setSsEndpointCompanionDescriptor(JNIEnv*,
-    struct libusb_ss_endpoint_companion_descriptor*, jobject);
+    const struct libusb_ss_endpoint_companion_descriptor*, jobject);
 struct libusb_ss_endpoint_companion_descriptor*
     unwrapSsEndpointCompanionDescriptor(JNIEnv*, jobject);
 void resetSsEndpointCompanionDescriptor(JNIEnv*, jobject);
diff --git a/src/main/c/src/SsUsbDeviceCapabilityDescriptor.c b/src/main/c/src/SsUsbDeviceCapabilityDescriptor.c
index 26dc131..03e8aa4 100644
--- a/src/main/c/src/SsUsbDeviceCapabilityDescriptor.c
+++ b/src/main/c/src/SsUsbDeviceCapabilityDescriptor.c
@@ -6,7 +6,7 @@
 #include "SsUsbDeviceCapabilityDescriptor.h"
 
 void setSsUsbDeviceCapabilityDescriptor(JNIEnv* env,
-    struct libusb_ss_usb_device_capability_descriptor* descriptor, jobject object)
+    const struct libusb_ss_usb_device_capability_descriptor* descriptor, jobject object)
 {
     SET_POINTER(env, descriptor, object, "ssUsbDeviceCapabilityDescriptorPointer");
 }
@@ -35,7 +35,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(SsUsbDeviceCapabilityDescriptor, bLength)
     struct libusb_ss_usb_device_capability_descriptor *descriptor =
         unwrapSsUsbDeviceCapabilityDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bLength;
+    return (jbyte) descriptor->bLength;
 }
 
 /**
@@ -49,7 +49,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(SsUsbDeviceCapabilityDescriptor, bDescriptor
     struct libusb_ss_usb_device_capability_descriptor *descriptor =
         unwrapSsUsbDeviceCapabilityDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bDescriptorType;
+    return (jbyte) descriptor->bDescriptorType;
 }
 
 /**
@@ -64,11 +64,11 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(SsUsbDeviceCapabilityDescriptor,
     struct libusb_ss_usb_device_capability_descriptor *descriptor =
         unwrapSsUsbDeviceCapabilityDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bDevCapabilityType;
+    return (jbyte) descriptor->bDevCapabilityType;
 }
 
 /**
- * int bmAttributes()
+ * byte bmAttributes()
  */
 JNIEXPORT jbyte JNICALL METHOD_NAME(SsUsbDeviceCapabilityDescriptor,
     bmAttributes)
@@ -79,7 +79,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(SsUsbDeviceCapabilityDescriptor,
     struct libusb_ss_usb_device_capability_descriptor *descriptor =
         unwrapSsUsbDeviceCapabilityDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bmAttributes;
+    return (jbyte) descriptor->bmAttributes;
 }
 
 /**
@@ -94,7 +94,7 @@ JNIEXPORT jshort JNICALL METHOD_NAME(SsUsbDeviceCapabilityDescriptor,
     struct libusb_ss_usb_device_capability_descriptor *descriptor =
         unwrapSsUsbDeviceCapabilityDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->wSpeedSupported;
+    return (jshort) descriptor->wSpeedSupported;
 }
 
 /**
@@ -109,7 +109,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(SsUsbDeviceCapabilityDescriptor,
     struct libusb_ss_usb_device_capability_descriptor *descriptor =
         unwrapSsUsbDeviceCapabilityDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bFunctionalitySupport;
+    return (jbyte) descriptor->bFunctionalitySupport;
 }
 
 /**
@@ -124,7 +124,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(SsUsbDeviceCapabilityDescriptor,
     struct libusb_ss_usb_device_capability_descriptor *descriptor =
         unwrapSsUsbDeviceCapabilityDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bU1DevExitLat;
+    return (jbyte) descriptor->bU1DevExitLat;
 }
 
 /**
@@ -139,5 +139,5 @@ JNIEXPORT jshort JNICALL METHOD_NAME(SsUsbDeviceCapabilityDescriptor,
     struct libusb_ss_usb_device_capability_descriptor *descriptor =
         unwrapSsUsbDeviceCapabilityDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bU2DevExitLat;
+    return (jshort) descriptor->bU2DevExitLat;
 }
diff --git a/src/main/c/src/SsUsbDeviceCapabilityDescriptor.h b/src/main/c/src/SsUsbDeviceCapabilityDescriptor.h
index bbeddbb..bd35734 100644
--- a/src/main/c/src/SsUsbDeviceCapabilityDescriptor.h
+++ b/src/main/c/src/SsUsbDeviceCapabilityDescriptor.h
@@ -9,7 +9,7 @@
 #include "usb4java.h"
 
 void setSsUsbDeviceCapabilityDescriptor(JNIEnv*,
-    struct libusb_ss_usb_device_capability_descriptor*, jobject);
+    const struct libusb_ss_usb_device_capability_descriptor*, jobject);
 struct libusb_ss_usb_device_capability_descriptor*
     unwrapSsUsbDeviceCapabilityDescriptor(JNIEnv*, jobject);
 void resetSsUsbDeviceCapabilityDescriptor(JNIEnv*, jobject);
diff --git a/src/main/c/src/Usb20ExtensionDescriptor.c b/src/main/c/src/Usb20ExtensionDescriptor.c
index 553b62b..e201d48 100644
--- a/src/main/c/src/Usb20ExtensionDescriptor.c
+++ b/src/main/c/src/Usb20ExtensionDescriptor.c
@@ -6,7 +6,7 @@
 #include "Usb20ExtensionDescriptor.h"
 
 void setUsb20ExtensionDescriptor(JNIEnv* env,
-    struct libusb_usb_2_0_extension_descriptor* descriptor, jobject object)
+    const struct libusb_usb_2_0_extension_descriptor* descriptor, jobject object)
 {
     SET_POINTER(env, descriptor, object, "usb20ExtensionDescriptorPointer");
 }
@@ -35,7 +35,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(Usb20ExtensionDescriptor, bLength)
     struct libusb_usb_2_0_extension_descriptor *descriptor =
         unwrapUsb20ExtensionDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bLength;
+    return (jbyte) descriptor->bLength;
 }
 
 /**
@@ -49,7 +49,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(Usb20ExtensionDescriptor, bDescriptorType)
     struct libusb_usb_2_0_extension_descriptor *descriptor =
         unwrapUsb20ExtensionDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bDescriptorType;
+    return (jbyte) descriptor->bDescriptorType;
 }
 
 /**
@@ -64,7 +64,7 @@ JNIEXPORT jbyte JNICALL METHOD_NAME(Usb20ExtensionDescriptor,
     struct libusb_usb_2_0_extension_descriptor *descriptor =
         unwrapUsb20ExtensionDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bDevCapabilityType;
+    return (jbyte) descriptor->bDevCapabilityType;
 }
 
 /**
@@ -79,5 +79,5 @@ JNIEXPORT jint JNICALL METHOD_NAME(Usb20ExtensionDescriptor,
     struct libusb_usb_2_0_extension_descriptor *descriptor =
         unwrapUsb20ExtensionDescriptor(env, this);
     if (!descriptor) return 0;
-    return descriptor->bmAttributes;
+    return (jint) descriptor->bmAttributes;
 }
diff --git a/src/main/c/src/Usb20ExtensionDescriptor.h b/src/main/c/src/Usb20ExtensionDescriptor.h
index d076ec4..ec57bc9 100644
--- a/src/main/c/src/Usb20ExtensionDescriptor.h
+++ b/src/main/c/src/Usb20ExtensionDescriptor.h
@@ -9,7 +9,7 @@
 #include "usb4java.h"
 
 void setUsb20ExtensionDescriptor(JNIEnv*,
-    struct libusb_usb_2_0_extension_descriptor*, jobject);
+    const struct libusb_usb_2_0_extension_descriptor*, jobject);
 struct libusb_usb_2_0_extension_descriptor*
     unwrapUsb20ExtensionDescriptor(JNIEnv*, jobject);
 void resetUsb20ExtensionDescriptor(JNIEnv*, jobject);
diff --git a/src/main/c/src/usb4java.h b/src/main/c/src/usb4java.h
index 5f29849..f9bb518 100644
--- a/src/main/c/src/usb4java.h
+++ b/src/main/c/src/usb4java.h
@@ -51,11 +51,11 @@
 // GetDirectBufferAddress returns NULL if called on a non-direct buffer.
 #define DIRECT_BUFFER(ENV, VAR, BUFFER, ACTION) \
     unsigned char *BUFFER = (*ENV)->GetDirectBufferAddress(ENV, VAR); \
-	if (!BUFFER) \
-	{ \
-	    illegalArgument(ENV, #VAR" must be a direct buffer"); \
-	    ACTION; \
-	}
+    if (!BUFFER) \
+    { \
+        illegalArgument(ENV, #VAR" must be a direct buffer"); \
+        ACTION; \
+    }
 
 #define NOT_NULL(ENV, VAR, ACTION) \
     if (!VAR) \
diff --git a/src/main/c/src/wrappers.c b/src/main/c/src/wrappers.c
new file mode 100644
index 0000000..f11f829
--- /dev/null
+++ b/src/main/c/src/wrappers.c
@@ -0,0 +1,15 @@
+/*
+ * Copyright (C) 2013 Klaus Reimer (k@ailis.de)
+ * See COPYING file for copying conditions
+ */
+
+#include <string.h>
+
+// Enforce usage of older memcpy to be compatible with older libc versions
+#ifdef WRAP_MEMCPY
+asm (".symver memcpy, memcpy@GLIBC_2.2.5");
+void *__wrap_memcpy(void *dest, const void *src, size_t n)
+{
+    return memcpy(dest, src, n);
+}
+#endif
diff --git a/src/main/java/de/ailis/usb4java/libusb/SsEndpointCompanionDescriptor.java b/src/main/java/de/ailis/usb4java/libusb/SsEndpointCompanionDescriptor.java
index 1f7e6da..eb726b7 100644
--- a/src/main/java/de/ailis/usb4java/libusb/SsEndpointCompanionDescriptor.java
+++ b/src/main/java/de/ailis/usb4java/libusb/SsEndpointCompanionDescriptor.java
@@ -32,7 +32,7 @@ import org.apache.commons.lang3.builder.HashCodeBuilder;
 public final class SsEndpointCompanionDescriptor
 {
     /** The native pointer to the descriptor structure. */
-    private long ssEndpointCompanionDescriptor;
+    private long ssEndpointCompanionDescriptorPointer;
 
     /**
      * Constructs a new descriptor which can be passed to the
@@ -52,7 +52,7 @@ public final class SsEndpointCompanionDescriptor
      */
     public long getPointer()
     {
-        return this.ssEndpointCompanionDescriptor;
+        return this.ssEndpointCompanionDescriptorPointer;
     }
 
     /**