diff --git a/Xext/vidmode.c b/Xext/vidmode.c
index c7c61647e..fc4670d41 100644
--- a/Xext/vidmode.c
+++ b/Xext/vidmode.c
@@ -808,6 +808,8 @@ ProcVidModeModModeLine(ClientPtr client)
         return BadValue;
 
     modetmp = VidModeCreateMode();
+    if (modetmp == NULL)
+        return BadAlloc;
     VidModeCopyMode(mode, modetmp);
 
     VidModeSetModeValue(modetmp, VIDMODE_H_DISPLAY, stuff->hdisplay);
@@ -951,6 +953,8 @@ ProcVidModeValidateModeLine(ClientPtr client)
         return BadValue;
 
     modetmp = VidModeCreateMode();
+    if (modetmp == NULL)
+        return BadAlloc;
     VidModeCopyMode(mode, modetmp);
 
     VidModeSetModeValue(modetmp, VIDMODE_H_DISPLAY, stuff->hdisplay);