diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 960df751..7a7ab76e 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -1,7 +1,7 @@
 name: CI
 on:
   push:
-    branches: [ master, feature/github-actions-for-windows-compilers ]
+    branches: [ feature/github-actions-for-windows-compilers ]
   pull_request:
     branches: [ master ]
 
@@ -30,5 +30,5 @@ jobs:
 
     - name: Build and run
       run: |
-        cmake -DNO_STL=1 ./
+        cmake -DNO_STL=ON ./
         MSBuild etl.sln
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index a0bebd0e..1cbd99a0 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -3,7 +3,9 @@ project(etl_unit_tests)
 
 add_definitions(-DETL_DEBUG)
 
-if (${NO_STL})
+option(NO_STL "No STL" OFF)
+
+if (NO_STL)
 	message(STATUS "Compiling for No STL")
 	add_definitions(-DETL_NO_STL)
 endif()