diff --git a/src/zm_monitor.cpp b/src/zm_monitor.cpp
index b66341beb..0630939db 100644
--- a/src/zm_monitor.cpp
+++ b/src/zm_monitor.cpp
@@ -557,7 +557,7 @@ bool Monitor::connect() {
   Debug(3, "Connecting to monitor.  Purpose is %d", purpose );
 #if ZM_MEM_MAPPED
   snprintf(mem_file, sizeof(mem_file), "%s/zm.mmap.%d", staticConfig.PATH_MAP.c_str(), id);
-  map_fd = open(mem_file, O_RDWR|O_CREAT, (mode_t)0600);
+  map_fd = open(mem_file, O_RDWR|O_CREAT, (mode_t)0660);
   if ( map_fd < 0 ) {
     Error("Can't open memory map file %s, probably not enough space free: %s", mem_file, strerror(errno));
     return false;