diff --git a/ci/env.sh b/ci/env.sh
index 34a48d63d4..ee383f69cf 100644
--- a/ci/env.sh
+++ b/ci/env.sh
@@ -59,7 +59,7 @@ if [[ -n $CI ]]; then
     fi
     if [[ $CI_LINUX = True ]]; then
       export CI_OS_NAME=linux
-    elif [[ $CI_WINDOWS = True ]]; then
+    else
       export CI_OS_NAME=windows
     fi
     export CI_REPO_SLUG=$APPVEYOR_REPO_NAME
diff --git a/ci/publish-tarball.sh b/ci/publish-tarball.sh
index 9aec9e0ca6..72bef3eff5 100755
--- a/ci/publish-tarball.sh
+++ b/ci/publish-tarball.sh
@@ -49,7 +49,8 @@ windows)
   TARGET=x86_64-pc-windows-msvc
   ;;
 *)
-  TARGET=unknown-unknown-unknown
+  echo CI_OS_NAME unset
+  exit 1
   ;;
 esac