diff --git a/src/eval.c b/src/eval.c
index d633f45..5a4ed67 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -1283,7 +1283,7 @@
 	text_indent_len = -1;
     }
 
-    // The marker is the next word.  Default marker is "."
+    // The marker is the next word.
     if (*cmd != NUL && *cmd != '"')
     {
 	marker = skipwhite(cmd);
@@ -1294,9 +1294,17 @@
 	    return NULL;
 	}
 	*p = NUL;
+	if (vim_islower(*marker))
+	{
+	    emsg(_("E221: Marker cannot start with lower case letter"));
+	    return NULL;
+	}
     }
     else
-	marker = (char_u *)".";
+    {
+	emsg(_("E172: Missing marker"));
+	return NULL;
+    }
 
     l = list_alloc();
     if (l == NULL)