diff --git a/core/ipc.cr b/core/ipc.cr
index 12b3c8c..1ff516b 100644
--- a/core/ipc.cr
+++ b/core/ipc.cr
@@ -145,10 +145,8 @@ end
 
 class IPC::Message
 	enum Type
-		CLOSE
-		CONNECTION
-		SYN
-		ACK
+		SERVER_CLOSE
+		ERROR
 		DATA
 	end
 
diff --git a/core/msg.h b/core/msg.h
index 48e306e..190b89d 100644
--- a/core/msg.h
+++ b/core/msg.h
@@ -5,13 +5,14 @@
 #include <stdlib.h>
 #include <string.h>
 
-// FIXME, removed messages types: MSG_TYPE_CON, MSG_TYPE_CLOSE, MSG_TYPE_ACK
-// this implies an underlying communication that is always correctly handled by the system
+// the underlying communication must always correctly handled by the system
 // (currently: unix sockets)
 
-#define MSG_TYPE_SERVER_CLOSE       0
-#define MSG_TYPE_ERR                1
-#define MSG_TYPE_DATA               2
+enum msg_types {
+	MSG_TYPE_SERVER_CLOSE = 0
+	, MSG_TYPE_ERR
+	, MSG_TYPE_DATA
+} message_types;
 
 struct ipc_message {
     char type;