diff --git a/src/display/webgl.js b/src/display/webgl.js
index cfef4c865..76dd0f67c 100644
--- a/src/display/webgl.js
+++ b/src/display/webgl.js
@@ -406,6 +406,14 @@ var WebGLUtils = (function WebGLUtilsClosure() {
   }
 
   function cleanup() {
+    if (smaskCache && smaskCache.canvas) {
+      smaskCache.canvas.width = 0;
+      smaskCache.canvas.height = 0;
+    }
+    if (figuresCache && figuresCache.canvas) {
+      figuresCache.canvas.width = 0;
+      figuresCache.canvas.height = 0;
+    }
     smaskCache = null;
     figuresCache = null;
   }