diff --git a/dcrjson/cmdparse.go b/dcrjson/cmdparse.go
index a583d5c0..a10f8493 100644
--- a/dcrjson/cmdparse.go
+++ b/dcrjson/cmdparse.go
@@ -447,7 +447,7 @@ func assignField(paramNum int, fieldName string, dest reflect.Value, src reflect
 
 		// String -> float of varying size.
 		case reflect.Float32, reflect.Float64:
-			srcFloat, err := strconv.ParseFloat(src.String(), 0)
+			srcFloat, err := strconv.ParseFloat(src.String(), 64)
 			if err != nil {
 				str := fmt.Sprintf("parameter #%d '%s' must "+
 					"parse to a %v", paramNum, fieldName,
diff --git a/dcrjson/help_test.go b/dcrjson/help_test.go
index 97035a12..c8a41848 100644
--- a/dcrjson/help_test.go
+++ b/dcrjson/help_test.go
@@ -172,6 +172,7 @@ func TestHelpReflectInternals(t *testing.T) {
 			name: "array of struct indent level 0",
 			reflectType: func() reflect.Type {
 				type s struct {
+					// nolint: structcheck, unused
 					field int
 				}
 				return reflect.TypeOf([]s{})
@@ -191,6 +192,7 @@ func TestHelpReflectInternals(t *testing.T) {
 			name: "array of struct indent level 1",
 			reflectType: func() reflect.Type {
 				type s struct {
+					// nolint: structcheck, unused
 					field int
 				}
 				return reflect.TypeOf([]s{})
@@ -308,6 +310,7 @@ func TestResultStructHelp(t *testing.T) {
 			name: "struct with primitive field",
 			reflectType: func() reflect.Type {
 				type s struct {
+					// nolint: structcheck, unused
 					field int
 				}
 				return reflect.TypeOf(s{})
@@ -332,6 +335,7 @@ func TestResultStructHelp(t *testing.T) {
 			name: "struct with array of primitive field",
 			reflectType: func() reflect.Type {
 				type s struct {
+					// nolint: structcheck, unused
 					field []int
 				}
 				return reflect.TypeOf(s{})
@@ -343,10 +347,12 @@ func TestResultStructHelp(t *testing.T) {
 		{
 			name: "struct with sub-struct field",
 			reflectType: func() reflect.Type {
+				// nolint: structcheck, unused
 				type s2 struct {
 					subField int
 				}
 				type s struct {
+					// nolint: structcheck, unused
 					field s2
 				}
 				return reflect.TypeOf(s{})
@@ -361,10 +367,12 @@ func TestResultStructHelp(t *testing.T) {
 		{
 			name: "struct with sub-struct field pointer",
 			reflectType: func() reflect.Type {
+				// nolint: structcheck, unused
 				type s2 struct {
 					subField int
 				}
 				type s struct {
+					// nolint: structcheck, unused
 					field *s2
 				}
 				return reflect.TypeOf(s{})
@@ -379,10 +387,12 @@ func TestResultStructHelp(t *testing.T) {
 		{
 			name: "struct with array of structs field",
 			reflectType: func() reflect.Type {
+				// nolint: structcheck, unused
 				type s2 struct {
 					subField int
 				}
 				type s struct {
+					// nolint: structcheck, unused
 					field []s2
 				}
 				return reflect.TypeOf(s{})
diff --git a/dcrjson/register_test.go b/dcrjson/register_test.go
index 4a7db7d6..ff4e5218 100644
--- a/dcrjson/register_test.go
+++ b/dcrjson/register_test.go
@@ -122,6 +122,7 @@ func TestRegisterCmdErrors(t *testing.T) {
 			name:   "embedded field",
 			method: "registertestcmd",
 			cmdFunc: func() interface{} {
+				// nolint: unused
 				type test struct{ int }
 				return (*test)(nil)
 			},
@@ -131,6 +132,7 @@ func TestRegisterCmdErrors(t *testing.T) {
 			name:   "unexported field",
 			method: "registertestcmd",
 			cmdFunc: func() interface{} {
+				// nolint: structcheck, unused
 				type test struct{ a int }
 				return (*test)(nil)
 			},