diff --git a/src/Main/options.cxx b/src/Main/options.cxx
index 5071f4362..180b12fd6 100644
--- a/src/Main/options.cxx
+++ b/src/Main/options.cxx
@@ -1457,16 +1457,16 @@ struct OptionDesc {
 #ifdef FG_JPEG_SERVER
     {"jpg-httpd",                    true,  OPTION_CHANNEL, "", false, "", 0 },
 #endif
-    {"native",                       true,  OPTION_CHANNEL, "", false, "", 0 },
-    {"native-ctrls",                 true,  OPTION_CHANNEL, "", false, "", 0 },
-    {"native-fdm",                   true,  OPTION_CHANNEL, "", false, "", 0 },
-    {"native-gui",                   true,  OPTION_CHANNEL, "", false, "", 0 },
-    {"opengc",                       true,  OPTION_CHANNEL, "", false, "", 0 },
-    {"AV400",                        true,  OPTION_CHANNEL, "", false, "", 0 },
-    {"AV400Sim",                     true,  OPTION_CHANNEL, "", false, "", 0 },
-    {"AV400WSimA",                   true,  OPTION_CHANNEL, "", false, "", 0 },
-    {"AV400WSimB",                   true,  OPTION_CHANNEL, "", false, "", 0 },
-    {"garmin",                       true,  OPTION_CHANNEL, "", false, "", 0 },
+    {"native",                       true,  OPTION_CHANNEL | OPTION_MULTI, "", false, "", 0 },
+    {"native-ctrls",                 true,  OPTION_CHANNEL | OPTION_MULTI, "", false, "", 0 },
+    {"native-fdm",                   true,  OPTION_CHANNEL | OPTION_MULTI, "", false, "", 0 },
+    {"native-gui",                   true,  OPTION_CHANNEL | OPTION_MULTI, "", false, "", 0 },
+    {"opengc",                       true,  OPTION_CHANNEL | OPTION_MULTI, "", false, "", 0 },
+    {"AV400",                        true,  OPTION_CHANNEL | OPTION_MULTI, "", false, "", 0 },
+    {"AV400Sim",                     true,  OPTION_CHANNEL | OPTION_MULTI, "", false, "", 0 },
+    {"AV400WSimA",                   true,  OPTION_CHANNEL | OPTION_MULTI, "", false, "", 0 },
+    {"AV400WSimB",                   true,  OPTION_CHANNEL | OPTION_MULTI, "", false, "", 0 },
+    {"garmin",                       true,  OPTION_CHANNEL | OPTION_MULTI, "", false, "", 0 },
     {"nmea",                         true,  OPTION_CHANNEL | OPTION_MULTI, "", false, "", 0 },
     {"generic",                      true,  OPTION_CHANNEL | OPTION_MULTI, "", false, "", 0 },
     {"props",                        true,  OPTION_CHANNEL | OPTION_MULTI, "", false, "", 0 },
@@ -1482,8 +1482,8 @@ struct OptionDesc {
 #ifdef FG_HAVE_HLA
     {"hla",                          true,  OPTION_CHANNEL, "", false, "", 0 },
 #endif
-    {"trace-read",                   true,  OPTION_FUNC,   "", false, "", fgOptTraceRead },
-    {"trace-write",                  true,  OPTION_FUNC,   "", false, "", fgOptTraceWrite },
+    {"trace-read",                   true,  OPTION_FUNC | OPTION_MULTI,   "", false, "", fgOptTraceRead },
+    {"trace-write",                  true,  OPTION_FUNC | OPTION_MULTI,   "", false, "", fgOptTraceWrite },
     {"log-level",                    true,  OPTION_FUNC,   "", false, "", fgOptLogLevel },
     {"view-offset",                  true,  OPTION_FUNC | OPTION_MULTI,   "", false, "", fgOptViewOffset },
     {"visibility",                   true,  OPTION_FUNC,   "", false, "", fgOptVisibilityMeters },