diff --git a/.github/workflows/publish-docker.yml b/.github/workflows/publish-docker.yml
index 46ec743..13970ad 100644
--- a/.github/workflows/publish-docker.yml
+++ b/.github/workflows/publish-docker.yml
@@ -8,7 +8,7 @@ permissions:
   packages: read
 
 env:
-  DOTNET_TARGET_VER: 9.0
+  DOTNET_TARGET_VER: '9.0'
 
 jobs:
   docker-linux: