--- a/src/qfits_memory.c
+++ b/src/qfits_memory.c
@@ -308,7 +308,7 @@
         /* Create swap file with rights: rw-rw-rw- */
         swapfileid = ++ qfits_memory_table.file_reg ;
         fname = qfits_memory_tmpfilename(swapfileid);
-        swapfd = open(fname, O_RDWR | O_CREAT);
+        swapfd = open(fname, O_RDWR | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH);
         if (swapfd==-1) {
             fprintf(stderr, "qfits_mem: cannot create swap file\n");
             exit(-1);