diff --git a/configure b/configure
index c6262468f7..80879aa1f8 100755
--- a/configure
+++ b/configure
@@ -7518,7 +7518,7 @@ ff_config_enable () {
 _nprefix=$3;
 test -z "$_nprefix" && _nprefix='CONFIG'
 for part in $1; do
-  if ` echo $2 | grep "[^ ]$part[ $]" > /dev/null `; then
+  if ` echo $2 | grep "\<$part\>" > /dev/null `; then
     echo "#define ${_nprefix}_$part 1"
     echo "#define ENABLE_$part 1"
   else