diff --git a/src/plugins/platforms/drm/egl_gbm_backend.cpp b/src/plugins/platforms/drm/egl_gbm_backend.cpp
index 8be45d4f76..d13723af8f 100644
--- a/src/plugins/platforms/drm/egl_gbm_backend.cpp
+++ b/src/plugins/platforms/drm/egl_gbm_backend.cpp
@@ -394,7 +394,7 @@ bool EglGbmBackend::initBufferConfigs()
 
     qCDebug(KWIN_DRM) << "EGL buffer configs count:" << count;
 
-    uint32_t fallbackFormat;
+    uint32_t fallbackFormat = 0;
     EGLConfig fallbackConfig = nullptr;
 
     // Loop through all configs, choosing the first one that has suitable format.