diff --git a/builder/actions/cmake.py b/builder/actions/cmake.py
index 45dd0f400..4031aee7d 100644
--- a/builder/actions/cmake.py
+++ b/builder/actions/cmake.py
@@ -189,7 +189,7 @@ def _build_project(env, project, cmake_extra, build_tests=False, args_transforme
     # as off. Without UniqueList cmake will treat it as on.
     cmake_args += project.cmake_args(env)
     cmake_args += cmake_extra
-    cmake_args += '-DCMAKE_VERBOSE_MAKEFILE=ON'
+    cmake_args += ['-DCMAKE_VERBOSE_MAKEFILE=ON']
     if coverage:
         if c_path and "gcc" in c_path:
             # Tell cmake to add coverage related configuration. And make sure GCC is used to compile the project.