diff --git a/src/add-ons/screen_savers/ifs/IFSSaver.cpp b/src/add-ons/screen_savers/ifs/IFSSaver.cpp
index 8aabbc3c4a..5a71e1be3a 100644
--- a/src/add-ons/screen_savers/ifs/IFSSaver.cpp
+++ b/src/add-ons/screen_savers/ifs/IFSSaver.cpp
@@ -190,10 +190,11 @@ IFSSaver::Draw(BView *view, int32 frame)
 		view->FillRect(view->Bounds());
 	}
 	int32 frames = frame - fLastDrawnFrame;
-	if (fIsPreview || fDirectInfo.bits == NULL) {
+	if ((fIsPreview || fDirectInfo.bits == NULL) && fLocker.Lock()) {
 		fIFS->Draw(view, NULL, frames);
 
 		fLastDrawnFrame = frame;
+		fLocker.Unlock();
 	}
 }