diff --git a/dix/pixmap.c b/dix/pixmap.c
index 1186d7dbbf62a5d0c11c43ed1f603ab4f457c882..5a0146bbb667a07bee5b53ff5390e435976d2d4b 100644
--- a/dix/pixmap.c
+++ b/dix/pixmap.c
@@ -116,7 +116,7 @@ AllocatePixmap(ScreenPtr pScreen, int pixDataSize)
     if (pScreen->totalPixmapSize > ((size_t) - 1) - pixDataSize)
         return NullPixmap;
 
-    pPixmap = malloc(pScreen->totalPixmapSize + pixDataSize);
+    pPixmap = calloc(1, pScreen->totalPixmapSize + pixDataSize);
     if (!pPixmap)
         return NullPixmap;