diff --git a/create_config b/create_config
index 23c0cd51f760f7a5b0230e25ce343f6a6c734e55..0098e683e20c9b7c600f712d0d6d6cf50f37517e 100755
--- a/create_config
+++ b/create_config
@@ -13,7 +13,7 @@ case $line in
     pkgversion=${line#*=}
     echo "#define QEMU_PKGVERSION \"$pkgversion\""
     ;;
- prefix=* | *dir=*) # directory configuration
+ prefix=* | [a-z]*dir=*) # directory configuration
     name=${line%=*}
     value=${line#*=}
     define_name=`echo $name | tr '[:lower:]' '[:upper:]'`