diff --git a/src/cf/linux-test1.m4 b/src/cf/linux-test1.m4
index 98bdc45c93..0b40eb75a5 100644
--- a/src/cf/linux-test1.m4
+++ b/src/cf/linux-test1.m4
@@ -29,7 +29,7 @@ MODULE_LICENSE("http://www.openafs.org/dl/license10.html");
 _ACEOF
     echo make -C $LINUX_KERNEL_BUILD M=$SRCDIR_PARENT/conftest.dir modules KBUILD_VERBOSE=1 >&AS_MESSAGE_LOG_FD &&
     make -C $LINUX_KERNEL_BUILD M=$SRCDIR_PARENT/conftest.dir modules KBUILD_VERBOSE=1 >&AS_MESSAGE_LOG_FD 2>conftest.err &&
-    ! grep -i "^WARNING: .* undefined!$" conftest.err >/dev/null 2>&1
+    ! grep -i "WARNING: .* undefined!$" conftest.err >/dev/null 2>&1
     then [$3]
     else
       sed '/^ *+/d' conftest.err >&AS_MESSAGE_LOG_FD