diff --git a/src/BackgroundSubtractor.cc b/src/BackgroundSubtractor.cc
index 3841cab..e9de264 100644
--- a/src/BackgroundSubtractor.cc
+++ b/src/BackgroundSubtractor.cc
@@ -126,6 +126,7 @@ NAN_METHOD(BackgroundSubtractorWrap::ApplyMOG) {
   catch( cv::Exception& e ){
     const char* err_msg = e.what();
     NanThrowError(err_msg);
+    NanReturnUndefined();
   }
 
 };
diff --git a/src/OpenCV.cc b/src/OpenCV.cc
index bb8635f..4ed6c43 100755
--- a/src/OpenCV.cc
+++ b/src/OpenCV.cc
@@ -72,5 +72,6 @@ NAN_METHOD(OpenCV::ReadImage) {
   } catch( cv::Exception& e ){
       const char* err_msg = e.what();
       NanThrowError(err_msg);
+      NanReturnUndefined();
   }
 };    
diff --git a/src/VideoCaptureWrap.cc b/src/VideoCaptureWrap.cc
index 89b17c0..6ccfaa3 100755
--- a/src/VideoCaptureWrap.cc
+++ b/src/VideoCaptureWrap.cc
@@ -180,7 +180,6 @@ class AsyncVCWorker : public NanAsyncWorker {
  private:
   VideoCaptureWrap *vc;
   Matrix* matrix;
-  int  res;
 };