--- a/src/memory.cpp
+++ b/src/memory.cpp
@@ -1872,7 +1872,7 @@
 	if (id == -1) {
 		nocanbang ();
 		if (recurse)
-			return NULL;
+			return false;
 		recurse++;
 		mapped_malloc (ab);
 		recurse--;
@@ -1904,7 +1904,7 @@
 		return ab->baseaddr != NULL;
 	}
 	if (recurse)
-		return NULL;
+		return false;
 	nocanbang ();
 	recurse++;
 	mapped_malloc (ab);
--- a/src/od-win32/picasso96_win.cpp
+++ b/src/od-win32/picasso96_win.cpp
@@ -3302,7 +3302,7 @@
 	if (NOBLITTER_BLIT)
 		return 0;
 	P96TRACE((_T("BlitRect(%d, %d, %d, %d, %d, %d, 0x%x)\n"), srcx, srcy, dstx, dsty, width, height, Mask));
-	result = BlitRect (renderinfo, (uaecptr)NULL, srcx, srcy, dstx, dsty, width, height, Mask, BLIT_SRC);
+	result = BlitRect (renderinfo, (uaecptr)0, srcx, srcy, dstx, dsty, width, height, Mask, BLIT_SRC);
 	return result;
 }
 
