diff --git a/buildspec.json b/buildspec.json
index 8aa70abe..fceb9383 100644
--- a/buildspec.json
+++ b/buildspec.json
@@ -39,7 +39,7 @@
         }
     },
     "name": "obs-backgroundremoval",
-    "version": "1.1.11",
+    "version": "1.1.12",
     "author": "Roy Shilkrot",
     "website": "https://github.com/royshil/obs-backgroundremoval",
     "email": "roy.shil@gmail.com",
diff --git a/src/background-filter.cpp b/src/background-filter.cpp
index 9a667220..9ce62a0b 100644
--- a/src/background-filter.cpp
+++ b/src/background-filter.cpp
@@ -585,7 +585,8 @@ void background_removal_thread(void *data)
 		}
 
 		if (tf->enableImageSimilarity) {
-			if (!lastImageBGRA.empty()) {
+			if (!lastImageBGRA.empty() && !imageBGRA.empty() &&
+			    lastImageBGRA.size() == imageBGRA.size()) {
 				// calculate PSNR
 				double psnr =
 					cv::PSNR(lastImageBGRA, imageBGRA);