diff --git a/kernel/Makefile b/kernel/Makefile
index b163f1056..685f322b1 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -201,7 +201,7 @@ update-kernel-hash-yaml-%:
 # find and replace any usage of the normal kernel with semver for most recent series
 update-kernel-semver-yaml-%:
 	$(eval NEWTAG=linuxkit/kernel:$*)
-	$(eval OLDTAG=linuxkit/kernel:[0-9]+.[0-9]+.[0-9]+$$$$)
+	$(eval OLDTAG=linuxkit/kernel:[0-9]+.[0-9]+.[0-9]+)
 	@cd $(REPO_ROOT) && ./scripts/update-component-sha.sh --hash "$(OLDTAG)" "$(NEWTAG)"
 
 # update-kernel-yamls updates the latest hash for each supported series,
diff --git a/scripts/update-component-sha.sh b/scripts/update-component-sha.sh
index 52e021de7..a65c62e52 100755
--- a/scripts/update-component-sha.sh
+++ b/scripts/update-component-sha.sh
@@ -69,8 +69,7 @@ case "${mode}" in
         fi
         old=$1
         new=$2
-
-        git grep -E -l "\b$old\b" -- '*.yml' '*.yaml' '*.yml.in' '*.yaml.in' '*/Dockerfile' '*/Makefile' | grep -v /vendor/ | while read -r file; do sed -ri.bak -e "s,$old,$new,g" "$file"; done
+        git grep -E -l "\b($old)([[:space:]].*)?$" -- '*.yml' '*.yaml' '*.yml.in' '*.yaml.in' '*/Dockerfile' '*/Makefile' | grep -v /vendor/ | while read -r file; do sed -ri.bak -e "s,$old,$new,g" "$file"; done
         ;;
 --image)
 	if [ $# -lt 1 ] ; then