diff --git a/config.w32 b/config.w32
index 9ac0a27..50e7ced 100644
--- a/config.w32
+++ b/config.w32
@@ -1,13 +1,12 @@
 // $Id$
 // vim:ft=javascript
 
-// If your extension references something external, use ARG_WITH
-// ARG_WITH("blenc", "for blenc support", "no");
-
-// Otherwise, use ARG_ENABLE
-// ARG_ENABLE("blenc", "enable blenc support", "no");
+ARG_ENABLE("blenc", "enable blenc support", "no");
 
 if (PHP_BLENC != "no") {
+	if (!PHP_BLENC_SHARED) {
+		ERROR("blenc can only be built as a shared extension");
+	}
+
 	EXTENSION("blenc", "blenc.c bf_algo.c");
 }
-