diff --git a/meson.build b/meson.build
index 235a67a5..8b536053 100644
--- a/meson.build
+++ b/meson.build
@@ -766,7 +766,7 @@ executable('ptraccel-debug',
 if is_debug_build
 	config_tool_option_test = configuration_data()
 	config_tool_option_test.set('DISABLE_WARNING', 'yes')
-	config_tool_option_test.set('MESON_ENABLED_DEBUG_GUI', get_option('debug-gui'))
+	config_tool_option_test.set('MESON_ENABLED_DEBUG_GUI', get_option('debug-gui').to_string())
 	config_tool_option_test.set('MESON_BUILD_ROOT', meson.current_build_dir())
 	config_tool_option_test.set('TOOL_PATH', libinput_tool.full_path())
 	tool_option_test = configure_file(input: 'tools/test_tool_option_parsing.py',
diff --git a/tools/test_tool_option_parsing.py b/tools/test_tool_option_parsing.py
index 8f5a006e..4114032f 100755
--- a/tools/test_tool_option_parsing.py
+++ b/tools/test_tool_option_parsing.py
@@ -117,7 +117,7 @@ class LibinputDebugGui(LibinputTool):
         assert subtool == "debug-gui"
         super().__init__(subtool)
 
-        debug_gui_enabled = "@MESON_ENABLED_DEBUG_GUI@" == "True"
+        debug_gui_enabled = "@MESON_ENABLED_DEBUG_GUI@".lower() == "true"
         if not debug_gui_enabled:
             pytest.skip()