diff --git a/Makefile-modules.mk b/Makefile-modules.mk
index 0c951fb0c..4ab29c1e4 100644
--- a/Makefile-modules.mk
+++ b/Makefile-modules.mk
@@ -4,8 +4,8 @@ MYGOBIN = $(shell go env GOPATH)/bin
 endif
 export PATH := $(MYGOBIN):$(PATH)
 
-export KUSTOMIZE_ROOT=$(shell pwd | sed 's|kustomize/.*|kustomize/|')
-
+# only set this if not already set, so importing makefiles can override it
+export KUSTOMIZE_ROOT ?= $(shell pwd | sed -E 's|(.*\/kustomize).*|\1|')
 include $(KUSTOMIZE_ROOT)/Makefile-tools.mk
 
 .PHONY: lint test fix fmt tidy vet
diff --git a/hack/for-each-module.sh b/hack/for-each-module.sh
index 17cb38499..e1b975615 100755
--- a/hack/for-each-module.sh
+++ b/hack/for-each-module.sh
@@ -15,8 +15,10 @@ fi
 
 cmd=$1
 
-seen=""
-kustomize_root=$(pwd | sed 's|kustomize/.*|kustomize/|')
+seen=()
+# Hack scripts must be run from the root of the repository.
+KUSTOMIZE_ROOT=$(pwd)
+export KUSTOMIZE_ROOT
 
 # verify all modules pass validation
 for i in $(find . -name go.mod -not -path "./site/*"); do
@@ -25,18 +27,25 @@ for i in $(find . -name go.mod -not -path "./site/*"); do
 
   set +x
   dir=$(pwd)
-  module="${dir#$kustomize_root}"
+  module="${dir#$KUSTOMIZE_ROOT}"
   echo -e "\n----------------------------------------------------------"
   echo "Running command in $module"
   echo -e "----------------------------------------------------------"
   set -x
 
   bash -c "$cmd"
-  seen+="  - $module\n"
+  seen+=("$module")
   popd
 done
 
 set +x
 echo -e "\n\n----------------------------------------------------------"
 echo -e "SUCCESS: Ran '$cmd' on the following modules:"
-echo -e "$seen"
+printf "  - %s\n" "${seen[@]}"
+
+EXPECTED_MODULE_COUNT=44
+if [[ "${#seen[@]}" -ne $EXPECTED_MODULE_COUNT ]]; then
+  echo
+  echo "SANITY CHECK FAILURE: Expected to see $EXPECTED_MODULE_COUNT modules, but saw ${#seen[@]}"
+  exit 1
+fi
diff --git a/kustomize/Makefile b/kustomize/Makefile
deleted file mode 120000
index d2f92ca51..000000000
--- a/kustomize/Makefile
+++ /dev/null
@@ -1 +0,0 @@
-../Makefile-modules.mk
\ No newline at end of file
diff --git a/kustomize/Makefile b/kustomize/Makefile
new file mode 100644
index 000000000..266eb4a6f
--- /dev/null
+++ b/kustomize/Makefile
@@ -0,0 +1,3 @@
+export KUSTOMIZE_ROOT=$(shell cd .. && pwd)
+
+include ../Makefile-modules.mk