diff --git a/SignalMessaging/contacts/OWSSyncManager.m b/SignalMessaging/contacts/OWSSyncManager.m
index 55eb0a73c7..c608207777 100644
--- a/SignalMessaging/contacts/OWSSyncManager.m
+++ b/SignalMessaging/contacts/OWSSyncManager.m
@@ -292,10 +292,13 @@ NSString *const kSyncManagerLastContactSyncKey = @"kTSStorageManagerOWSSyncManag
                               skipIfRedundant:(BOOL)skipIfRedundant
                                      debounce:(BOOL)debounce
 {
+    if (!self.tsAccountManager.isRegisteredPrimaryDevice) {
+        return [AnyPromise promiseWithValue:OWSErrorMakeAssertionError(@"should not sync from secondary device")];
+    }
+
     AnyPromise *promise = [AnyPromise promiseWithResolverBlock:^(PMKResolver resolve) {
         [AppReadiness runNowOrWhenAppDidBecomeReady:^{
             dispatch_async(self.serialQueue, ^{
-                OWSAssertDebug(self.tsAccountManager.isRegisteredPrimaryDevice);
                 if (debounce && self.isRequestInFlight) {
                     // De-bounce.  It's okay if we ignore some new changes;
                     // `sendSyncContactsMessageIfPossible` is called fairly
diff --git a/SignalServiceKit/src/Util/OWSUserProfile.m b/SignalServiceKit/src/Util/OWSUserProfile.m
index 6c0f0384e2..3480e4c70e 100644
--- a/SignalServiceKit/src/Util/OWSUserProfile.m
+++ b/SignalServiceKit/src/Util/OWSUserProfile.m
@@ -320,7 +320,8 @@ NSUInteger const kUserProfileSchemaVersion = 1;
                                           // We populate an initial (empty) profile on launch of a new install, but
                                           // until we have a registered account, syncing will fail (and there could not
                                           // be any linked device to sync to at this point anyway).
-                                          if ([self.tsAccountManager isRegistered] && CurrentAppContext().isMainApp) {
+                                          if (self.tsAccountManager.isRegisteredPrimaryDevice
+                                              && CurrentAppContext().isMainApp) {
                                               [[self.syncManager syncLocalContact] retainUntilComplete];
                                           }