diff --git a/misc_cmd.c b/misc_cmd.c
--- a/misc_cmd.c
+++ b/misc_cmd.c
@@ -129,6 +129,8 @@ int32 CmdChangeCompanyName(int x, int y,
 	StringID str;
 	Player *p;
 
+	if (_cmd_text[0] == '\0') return CMD_ERROR;
+
 	str = AllocateNameUnique(_cmd_text, 4);
 	if (str == 0) return CMD_ERROR;
 
@@ -153,6 +155,8 @@ int32 CmdChangePresidentName(int x, int 
 	StringID str;
 	Player *p;
 
+	if (_cmd_text[0] == '\0') return CMD_ERROR;
+
 	str = AllocateNameUnique(_cmd_text, 4);
 	if (str == 0) return CMD_ERROR;