diff --git a/toolkit/xre/nsAppRunner.cpp b/toolkit/xre/nsAppRunner.cpp
index 155d5c498..61c05ae2a 100644
--- a/toolkit/xre/nsAppRunner.cpp
+++ b/toolkit/xre/nsAppRunner.cpp
@@ -4189,9 +4189,12 @@ XRE_InitCommandLine(int aArgc, char* aArgv[])
 #endif
 
   const char *path = nullptr;
-  ArgResult ar = CheckArg("greomni", false, &path);
+  ArgResult ar = CheckArg("greomni", true, &path);
   if (ar == ARG_BAD) {
-    PR_fprintf(PR_STDERR, "Error: argument --greomni requires a path argument\n");
+    PR_fprintf(PR_STDERR, 
+               "Error: argument --greomni requires a path argument or the "
+               "--osint argument was specified with the --greomni argument "
+               "which is invalid.\n");
     return NS_ERROR_FAILURE;
   }
 
@@ -4205,9 +4208,12 @@ XRE_InitCommandLine(int aArgc, char* aArgv[])
     return rv;
   }
 
-  ar = CheckArg("appomni", false, &path);
+  ar = CheckArg("appomni", true, &path);
   if (ar == ARG_BAD) {
-    PR_fprintf(PR_STDERR, "Error: argument --appomni requires a path argument\n");
+    PR_fprintf(PR_STDERR,
+               "Error: argument --appomni requires a path argument or the "
+               "--osint argument was specified with the --appomni argument "
+               "which is invalid.\n");
     return NS_ERROR_FAILURE;
   }