diff --git a/build/autoconf/lustre-build-linux.m4 b/build/autoconf/lustre-build-linux.m4
index e4f39df78ff381887925b49d991dbfcb9e3dbd7c..f434e0ce0cfa065b107bbffc0f5ce6ad1a42e9b6 100644
--- a/build/autoconf/lustre-build-linux.m4
+++ b/build/autoconf/lustre-build-linux.m4
@@ -516,7 +516,7 @@ rc=$?
 if test $rc -ne 0; then
     export=0
     for file in $2; do
-    	grep -q -E "EXPORT_SYMBOL.*($1)" "$LINUX/$file" 2>/dev/null
+    	grep -q -E "EXPORT_SYMBOL.*\($1\)" "$LINUX/$file" 2>/dev/null
     	rc=$?
 	if test $rc -eq 0; then
 		export=1