diff --git a/.github/workflows/action.yml b/.github/workflows/action.yml
index 5e5d7a7..35e86fc 100644
--- a/.github/workflows/action.yml
+++ b/.github/workflows/action.yml
@@ -22,6 +22,7 @@ jobs:
 
     env:
       EASYRSA_REMOTE_CI: 1
+      EASYRSA_NIX: 1
       TERM: xterm-256color
 
     # Steps represent a sequence of tasks that will be executed as part of the job
@@ -30,9 +31,6 @@ jobs:
       - uses: actions/checkout@v2
 
       # Runs a single command using the runners shell
-      - name: shellcheck test
-        run: shellcheck -V
-        #run: shellcheck easyrsa3/easyrsa
       - name: operational test
         run: sh op_test.sh -v
 
@@ -49,6 +47,7 @@ jobs:
 
     env:
       EASYRSA_REMOTE_CI: 1
+      EASYRSA_WIN: 1
       TERM: xterm-256color
 
     # Steps represent a sequence of tasks that will be executed as part of the job
diff --git a/op_test.sh b/op_test.sh
index 80f210d..00c3e41 100644
--- a/op_test.sh
+++ b/op_test.sh
@@ -4,6 +4,22 @@
 # and executes that - allows for disconnected testing from the easy-rsa
 # repo with TravisCI.
 
+github_url='https://raw.githubusercontent.com'
+
+if [ -e "shellcheck" ] && [ "$EASYRSA_NIX" ]; then
+	chmod +x shellcheck
+	./shellcheck -V
+	./shellcheck easyrsa3/easyrsa
+elif [ "$EASYRSA_NIX" ]; then
+	github_target='OpenVPN/easyrsa-unit-tests/master/shellcheck'
+	curl -O "${github_url}/${github_target}"
+	[ -e "shellcheck" ] || { echo "shellcheck download failed."; exit 9; }
+	chmod +x shellcheck
+	./shellcheck -V
+	./shellcheck easyrsa3/easyrsa
+	rm -f ./shellcheck
+fi
+
 case "$1" in
 -v)		verb='-v' ;;
 -vv)	verb='-vv' ;;
@@ -13,13 +29,20 @@ esac
 estat=0
 
 if [ -e "easyrsa-unit-tests.sh" ]; then
-	sh easyrsa-unit-tests.sh "$verb"
-	estat=$?
+	if sh easyrsa-unit-tests.sh "$verb"; then
+		: # ok
+	else
+		estat=1
+	fi
 else
-	curl -O 'https://raw.githubusercontent.com/OpenVPN/easyrsa-unit-tests/master/easyrsa-unit-tests.sh'
+	github_target='OpenVPN/easyrsa-unit-tests/master/easyrsa-unit-tests.sh'
+	curl -O "${github_url}/${github_target}"
 	[ -e "easyrsa-unit-tests.sh" ] || { echo "Unit-test download failed."; exit 9; }
-	sh easyrsa-unit-tests.sh "$verb"
-	estat=$?
+	if sh easyrsa-unit-tests.sh "$verb"; then
+		: # ok
+	else
+		estat=1
+	fi
 	rm -f easyrsa-unit-tests.sh
 fi