diff --git a/lib/getdate.y b/lib/getdate.y
index 86a3d4691..9f8f95f1c 100644
--- a/lib/getdate.y
+++ b/lib/getdate.y
@@ -10,7 +10,7 @@
 
 #ifdef HAVE_CONFIG_H
 # include <config.h>
-# ifdef FORCE_ALLOCA_H
+# ifdef HAVE_ALLOCA_H
 #  include <alloca.h>
 # endif
 #endif