diff --git a/src/canvas.cc b/src/canvas.cc
index c13ad17..07bcf33 100644
--- a/src/canvas.cc
+++ b/src/canvas.cc
@@ -75,6 +75,7 @@ Canvas::SetWidth(Local<String> prop, Local<Value> val, const AccessorInfo &info)
   if (val->IsNumber()) {
     Canvas *canvas = ObjectWrap::Unwrap<Canvas>(info.This());
     canvas->width = val->Uint32Value();
+    canvas->resetSurface();
   }
 }
 
@@ -97,6 +98,7 @@ Canvas::SetHeight(Local<String> prop, Local<Value> val, const AccessorInfo &info
   if (val->IsNumber()) {
     Canvas *canvas = ObjectWrap::Unwrap<Canvas>(info.This());
     canvas->height = val->Uint32Value();
+    canvas->resetSurface();
   }
 }
 
diff --git a/src/canvas.h b/src/canvas.h
index 3f3a082..2648877 100644
--- a/src/canvas.h
+++ b/src/canvas.h
@@ -62,10 +62,10 @@ class Canvas: public node::ObjectWrap {
     inline cairo_surface_t *getSurface(){ return _surface; }
     static void blur(cairo_surface_t *surface, int radius);
     Canvas(int width, int height);
+    void resetSurface();
 
   private:
     ~Canvas();
-    void resetSurface();
     cairo_surface_t *_surface;
 };