diff --git a/src/mesa/main/shaderapi.c b/src/mesa/main/shaderapi.c
index 0ca4f58dd51..3e2f8839b86 100644
--- a/src/mesa/main/shaderapi.c
+++ b/src/mesa/main/shaderapi.c
@@ -1696,7 +1696,7 @@ _mesa_GetProgramBinary(GLuint program, GLsizei bufSize, GLsizei *length,
     * Ensure that length always points to valid storage to avoid multiple NULL
     * pointer checks below.
     */
-   if (length != NULL)
+   if (length == NULL)
       length = &length_dummy;