diff --git a/.github/workflows/compile-arduino.yml b/.github/workflows/compile-arduino.yml
index ef43a5c..45e688e 100644
--- a/.github/workflows/compile-arduino.yml
+++ b/.github/workflows/compile-arduino.yml
@@ -80,7 +80,7 @@ jobs:
           enable-deltas-report: "true"
           sketches-report-path: sketches-reports
           cli-compile-flags: |
-            --warnings="all"
+            - --warnings="all"
 #            - --build-property
 #            - compiler.cpp.extra_flag="-Wno-unused-function"
       - name: Report Arduino Sketch Size Deltas