diff --git a/packages/fcl-image/src/fpfont.inc b/packages/fcl-image/src/fpfont.inc
index af1e2b573f..e664a34b2e 100644
--- a/packages/fcl-image/src/fpfont.inc
+++ b/packages/fcl-image/src/fpfont.inc
@@ -54,7 +54,10 @@ begin
   if inheritsFrom (TFPCustomDrawFont) then
     result := TFPCustomDrawFont(self).DoGetTextHeight (text)
   else
-    result := FCanvas.GetTextHeight (text);
+   if assigned(FCanvas) then
+     result := FCanvas.GetTextHeight (text)
+   else 
+     result :=16; // *some* default better than none.
 end;
 
 function TFPCustomFont.GetTextWidth (text:string) : integer;