diff --git a/fpm/fpm.h b/fpm/fpm.h
index 70c0df5715..9003c643b0 100644
--- a/fpm/fpm.h
+++ b/fpm/fpm.h
@@ -65,7 +65,7 @@
 /*
  * Largest message that can be sent to or received from the FPM.
  */
-#define FPM_MAX_MSG_LEN 4096
+#define FPM_MAX_MSG_LEN MAX(MULTIPATH_NUM * 32, 4096)
 
 #ifdef __SUNPRO_C
 #pragma pack(1)