diff --git a/I1401/i1401_sys.c b/I1401/i1401_sys.c
index ba9e58c7..751298b8 100644
--- a/I1401/i1401_sys.c
+++ b/I1401/i1401_sys.c
@@ -93,13 +93,13 @@ const char *sim_stop_messages[SCPE_BASE] = {
     "Invalid A address",
     "Invalid B address",
     "Invalid instruction length",
-    "Invalid modifer",
+    "Invalid modifier",
     "Invalid branch address",
     "Breakpoint",
     "HALT instruction",
     "Invalid MT unit number",
     "Invalid MT record length",
-    "Write to locked MT unit",  
+    "Write to locked MT unit",
     "Skip to unpunched CCT channel",
     "Card reader empty",
     "Address register wrap",