diff --git a/progs/tests/manytex.c b/progs/tests/manytex.c
index 28f7d3b3f2d..900e5834fe8 100644
--- a/progs/tests/manytex.c
+++ b/progs/tests/manytex.c
@@ -133,6 +133,7 @@ static void DeleteTextures(void)
 {
    glDeleteTextures(NumTextures, TextureID);
    free(TextureID);
+   TextureID = NULL;
 }