diff --git a/doc/makepanda/config.in b/doc/makepanda/config.in
index e671742970..b5161fd4e1 100755
--- a/doc/makepanda/config.in
+++ b/doc/makepanda/config.in
@@ -86,3 +86,7 @@ hardware-animated-vertices 0
 model-cache-dir $THIS_PRC_DIR/../modelcache
 model-cache-textures #f
 
+# Limit the use of advanced shader profiles.
+# Currently, advanced profiles are not reliable under Cg.
+
+basic-shaders-only #t