diff --git a/PtpWebcamDalPlugin/PtpCamera.m b/PtpWebcamDalPlugin/PtpCamera.m
index 34fd213..f7da587 100644
--- a/PtpWebcamDalPlugin/PtpCamera.m
+++ b/PtpWebcamDalPlugin/PtpCamera.m
@@ -427,7 +427,7 @@ - (instancetype) initWithIcCamera: (ICCameraDevice*) camera delegate: (id <PtpCa
 - (void) dealloc
 {
 	if (frameTimerSource)
-		dispatch_suspend(frameTimerSource);
+		dispatch_source_cancel(frameTimerSource);
 }
 
 - (void) deviceDidBecomeReadyWithCompleteContentCatalog:(ICCameraDevice *)device
diff --git a/PtpWebcamDalPlugin/PtpWebcamDummyStream.m b/PtpWebcamDalPlugin/PtpWebcamDummyStream.m
index fd3323b..fb1a587 100644
--- a/PtpWebcamDalPlugin/PtpWebcamDummyStream.m
+++ b/PtpWebcamDalPlugin/PtpWebcamDummyStream.m
@@ -46,7 +46,8 @@ - (instancetype) init
 
 - (void) dealloc
 {
-	dispatch_suspend(frameTimerSource);
+	if (frameTimerSource)
+		dispatch_source_cancel(frameTimerSource);
 }
 
 - (OSStatus) startStream
@@ -58,7 +59,8 @@ - (OSStatus) startStream
 
 - (OSStatus) stopStream
 {
-	dispatch_suspend(frameTimerSource);
+	if (frameTimerSource)
+		dispatch_source_cancel(frameTimerSource);
 
 	return kCMIOHardwareNoError;
 }
diff --git a/PtpWebcamDalPlugin/PtpWebcamPtpStream.m b/PtpWebcamDalPlugin/PtpWebcamPtpStream.m
index 28f6c6c..9de1dbe 100644
--- a/PtpWebcamDalPlugin/PtpWebcamPtpStream.m
+++ b/PtpWebcamDalPlugin/PtpWebcamPtpStream.m
@@ -41,7 +41,7 @@ - (instancetype) initWithPluginInterface: (_Nonnull CMIOHardwarePlugInRef) plugi
 - (void) dealloc
 {
 	if (frameTimerSource)
-		dispatch_suspend(frameTimerSource);
+		dispatch_source_cancel(frameTimerSource);
 }
 
 - (void) startFrameTimer