diff --git a/content/canvas/src/nsCanvasRenderingContext2D.cpp b/content/canvas/src/nsCanvasRenderingContext2D.cpp
index ae9ac7ab9165..83a101cdaf9e 100644
--- a/content/canvas/src/nsCanvasRenderingContext2D.cpp
+++ b/content/canvas/src/nsCanvasRenderingContext2D.cpp
@@ -3362,7 +3362,9 @@ nsCanvasRenderingContext2D::DrawImage(nsIDOMElement *imgElt, float a1,
                                       float a6, float a7, float a8,
                                       PRUint8 optional_argc)
 {
-    NS_ENSURE_ARG(imgElt);
+    if (!imgElt) {
+        return NS_ERROR_DOM_TYPE_MISMATCH_ERR;
+    }
 
     double sx,sy,sw,sh;
     double dx,dy,dw,dh;
diff --git a/content/canvas/test/test_canvas.html b/content/canvas/test/test_canvas.html
index 91b4e4ce0baa..b2ba6ea318de 100644
--- a/content/canvas/test/test_canvas.html
+++ b/content/canvas/test/test_canvas.html
@@ -3497,7 +3497,7 @@ var ctx = canvas.getContext('2d');
 
 var _thrown = undefined; try {
   ctx.drawImage(null, 0, 0);
-} catch (e) { _thrown = e }; todo(_thrown && _thrown.code == DOMException.TYPE_MISMATCH_ERR, "should throw TYPE_MISMATCH_ERR");
+} catch (e) { _thrown = e }; ok(_thrown && _thrown.code == DOMException.TYPE_MISMATCH_ERR, "should throw TYPE_MISMATCH_ERR");
 
 
 }
@@ -3669,7 +3669,7 @@ var ctx = canvas.getContext('2d');
 
 var _thrown = undefined; try {
   ctx.drawImage(undefined, 0, 0);
-} catch (e) { _thrown = e }; ok(_thrown && _thrown.result == Components.results.NS_ERROR_INVALID_ARG, "should throw NS_ERROR_INVALID_ARG");
+} catch (e) { _thrown = e }; ok(_thrown && _thrown.code == DOMException.TYPE_MISMATCH_ERR, "should throw TYPE_MISMATCH_ERR");
 var _thrown = undefined; try {
   ctx.drawImage(0, 0, 0);
 } catch (e) { _thrown = e }; ok(_thrown && _thrown.result == Components.results.NS_ERROR_XPC_BAD_CONVERT_JS_ZERO_ISNOT_NULL, "should throw NS_ERROR_XPC_BAD_CONVERT_JS_ZERO_ISNOT_NULL");