diff --git a/src/common.h b/src/common.h
index 60e727d..a960dcd 100644
--- a/src/common.h
+++ b/src/common.h
@@ -35,7 +35,7 @@ using namespace std;
 using namespace std::filesystem;
 
 #define BUF_SZ  10
-#define APP_VER "1.4.t4"
+#define APP_VER "1.4.t5"
 
 struct shared_t
 {
diff --git a/src/mo_detect.h b/src/mo_detect.h
index 884091f..8a92550 100644
--- a/src/mo_detect.h
+++ b/src/mo_detect.h
@@ -24,7 +24,7 @@ struct sec_t
     int pixDiff;
 };
 
-void secDiff(Mat imgA, Mat imgB, int rows, int cols, int rowOffs, int colOffs, vector<sec_t> *results, mutex *secMutex, shared_t *share);
+void secDiff(const Mat &imgA, const Mat &imgB, int rows, int cols, int rowOffs, int colOffs, vector<sec_t> *results, mutex *secMutex, shared_t *share);
 bool pixDiff(const uchar &pixA, const uchar &pixB, shared_t *share);
 bool imgDiff(Mat prev, Mat next, Rect *block, shared_t *share);
 bool moDetect(const string &buffFile, Rect *block, Mat *img, shared_t *share);