--- a/src/deco-theme.hpp
+++ b/src/deco-theme.hpp
@@ -93,7 +93,7 @@
     wf::color_t bg;
     wf::color_t fg_text;
     wf::color_t bg_text;
-    bool maximized;
+    bool maximized = false;
     std::unique_ptr<PangoFontDescription, decltype(&pango_font_description_free)> font_description;
 };
 }