diff --git a/config/kernel.m4 b/config/kernel.m4
index 639d183771..ec61e2c8f1 100644
--- a/config/kernel.m4
+++ b/config/kernel.m4
@@ -394,11 +394,11 @@ AC_DEFUN([ZFS_AC_KERNEL], [
 	utsrelease1=$kernelbuild/include/linux/version.h
 	utsrelease2=$kernelbuild/include/linux/utsrelease.h
 	utsrelease3=$kernelbuild/include/generated/utsrelease.h
-	AS_IF([test -r $utsrelease1 && fgrep -q UTS_RELEASE $utsrelease1], [
+	AS_IF([test -r $utsrelease1 && grep -qF UTS_RELEASE $utsrelease1], [
 		utsrelease=$utsrelease1
-	], [test -r $utsrelease2 && fgrep -q UTS_RELEASE $utsrelease2], [
+	], [test -r $utsrelease2 && grep -qF UTS_RELEASE $utsrelease2], [
 		utsrelease=$utsrelease2
-	], [test -r $utsrelease3 && fgrep -q UTS_RELEASE $utsrelease3], [
+	], [test -r $utsrelease3 && grep -qF UTS_RELEASE $utsrelease3], [
 		utsrelease=$utsrelease3
 	])
 
diff --git a/config/zfs-build.m4 b/config/zfs-build.m4
index d516f3d296..726b4b420c 100644
--- a/config/zfs-build.m4
+++ b/config/zfs-build.m4
@@ -173,7 +173,7 @@ AC_DEFUN([ZFS_AC_DEBUG_KMEM_TRACKING], [
 ])
 
 AC_DEFUN([ZFS_AC_DEBUG_INVARIANTS_DETECT_FREEBSD], [
-	AS_IF([sysctl -n kern.conftxt | fgrep -qx $'options\tINVARIANTS'],
+	AS_IF([sysctl -n kern.conftxt | grep -Fqx $'options\tINVARIANTS'],
 		[enable_invariants="yes"],
 		[enable_invariants="no"])
 ])
diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_wait/zpool_wait.kshlib b/tests/zfs-tests/tests/functional/cli_root/zpool_wait/zpool_wait.kshlib
index b413f6e9f9..ccb9791496 100644
--- a/tests/zfs-tests/tests/functional/cli_root/zpool_wait/zpool_wait.kshlib
+++ b/tests/zfs-tests/tests/functional/cli_root/zpool_wait/zpool_wait.kshlib
@@ -120,5 +120,5 @@ function check_while_waiting
 # Whether any vdev in the given pool is initializing
 function is_vdev_initializing # pool
 {
-	zpool status -i "$1" | grep 'initialized, started' >/dev/null
+	zpool status -i "$1" | grep -q 'initialized, started'
 }