diff --git a/src/x11_init.c b/src/x11_init.c
index 982c526c..6b34c263 100644
--- a/src/x11_init.c
+++ b/src/x11_init.c
@@ -535,6 +535,7 @@ static void detectEWMH(void)
                                    XA_WINDOW,
                                    (unsigned char**) &windowFromChild))
     {
+        _glfwReleaseErrorHandlerX11();
         XFree(windowFromRoot);
         return;
     }