diff --git a/mozilla/gfx/src/os2/nsDeviceContextOS2.cpp b/mozilla/gfx/src/os2/nsDeviceContextOS2.cpp
index c388c507dbd..7011bafa381 100644
--- a/mozilla/gfx/src/os2/nsDeviceContextOS2.cpp
+++ b/mozilla/gfx/src/os2/nsDeviceContextOS2.cpp
@@ -390,6 +390,9 @@ void QueryFontFromINI(char* fontType, char* fontName, ULONG ulLength)
       else
         strcpy(fontName, "10.Helv Combined");
     }
+  } else {
+    /* null terminate fontname */
+    fontName[ulMaxNameL] = '\0';
   }
 }