diff --git a/src/mesa/main/context.c b/src/mesa/main/context.c
index 08db12b..fb5a68d 100644
--- a/src/mesa/main/context.c
+++ b/src/mesa/main/context.c
@@ -1499,6 +1499,11 @@ void
 _mesa_make_current( GLcontext *newCtx, GLframebuffer *drawBuffer,
                     GLframebuffer *readBuffer )
 {
+   if (newCtx) {
+      assert(drawBuffer);
+      assert(readBuffer);
+   }
+
    if (MESA_VERBOSE & VERBOSE_API)
       _mesa_debug(newCtx, "_mesa_make_current()\n");