diff --git a/imgui.cpp b/imgui.cpp
index 12e25ca..a97d077 100644
--- a/imgui.cpp
+++ b/imgui.cpp
@@ -4394,7 +4394,11 @@
     if (g.LogEnabled)
         return;
     if (!filename)
+    {
         filename = g.IO.LogFilename;
+        if (!filename)
+            return;
+    }
 
     g.LogFile = fopen(filename, "ab");
     if (!g.LogFile)