diff --git a/mxqsub.c b/mxqsub.c
index 5a48b0cb..43120341 100644
--- a/mxqsub.c
+++ b/mxqsub.c
@@ -70,8 +70,17 @@ static void print_usage(void)
     "  on the priority given to the job.\n"
     "\n"
     "  -j, --threads=NUMBER     set number of threads       (default: 1)\n"
-    "  -m, --memory=SIZE        set amount of memory in MiB (default: 2048)\n"
-    "  -t, --runtime=MINUTES    set runtime in minutes      (default: 15)\n"
+    "  -m, --memory=SIZE        set amount of memory        (default: 2G)\n"
+    "\n"
+    "        [SIZE] may be suffixed with a combination of T, G and M\n"
+    "               to specify tebibytes, gibibytes and mebibytes.\n"
+    "               Defaults to mebibytes if no suffix is set.\n"
+    "\n"
+    "  -t, --runtime=TIME       set runtime                 (default: 15m)\n"
+    "\n"
+    "        [TIME] may be suffixed with a combination of y, w, d, h and m\n"
+    "               to specify years, weeks, days, hours and minutes\n"
+    "               Defaults to minutes if no suffix is set.\n"
     "\n"
     "Job handling:\n"
     "  Define what to do if something bad happens:\n"