diff --git a/tools/sk_app/mac/GLWindowContext_mac.mm b/tools/sk_app/mac/GLWindowContext_mac.mm
index 0edcaa9..803eb23 100644
--- a/tools/sk_app/mac/GLWindowContext_mac.mm
+++ b/tools/sk_app/mac/GLWindowContext_mac.mm
@@ -51,6 +51,7 @@
 }
 
 GLWindowContext_mac::~GLWindowContext_mac() {
+    [NSOpenGLContext clearCurrentContext];
     [fPixelFormat release];
     fPixelFormat = nil;
     [fGLContext release];
diff --git a/tools/sk_app/mac/RasterWindowContext_mac.mm b/tools/sk_app/mac/RasterWindowContext_mac.mm
index 337a3fe..5b8d345 100644
--- a/tools/sk_app/mac/RasterWindowContext_mac.mm
+++ b/tools/sk_app/mac/RasterWindowContext_mac.mm
@@ -62,6 +62,7 @@
 }
 
 RasterWindowContext_mac::~RasterWindowContext_mac() {
+    [NSOpenGLContext clearCurrentContext];
     [fPixelFormat release];
     fPixelFormat = nil;
     [fGLContext release];