diff --git a/samplecode/SampleApp.cpp b/samplecode/SampleApp.cpp
index bc1b929..fd19e89 100644
--- a/samplecode/SampleApp.cpp
+++ b/samplecode/SampleApp.cpp
@@ -1051,7 +1051,9 @@
     int count = canvas->save();
     
     SkMatrix m = canvas->getTotalMatrix();
-    m.invert(&m);
+    if (!m.invert(&m)) {
+        return;
+    }
     SkPoint offset, center;
     SkScalar mouseX = fMouseX * SK_Scalar1;
     SkScalar mouseY = fMouseY * SK_Scalar1;