diff --git a/mozilla/modules/libimg/mng/mng_jpeg.c b/mozilla/modules/libimg/mng/mng_jpeg.c
index b0a2204fe9b..f8e578462c7 100644
--- a/mozilla/modules/libimg/mng/mng_jpeg.c
+++ b/mozilla/modules/libimg/mng/mng_jpeg.c
@@ -207,8 +207,10 @@ mng_retcode mngjpeg_cleanup (mng_datap pData)
     MNG_ERRORJ (pData, iRetcode)       /* then IJG-lib issued an error */
 #endif    
 
+#ifdef MNG_SUPPORT_WRITE
   if (pData->bJPEGcompress)            /* still compressing something ? */
     jpeg_destroy_compress (pData->pJPEGcinfo);
+#endif
 
   if (pData->bJPEGdecompress)          /* still decompressing something ? */
     jpeg_destroy_decompress (pData->pJPEGdinfo);