diff --git a/src/release.h b/src/release.h
index c106d622..7fccb73f 100644
--- a/src/release.h
+++ b/src/release.h
@@ -20,6 +20,11 @@
  *
  */
 
+#ifndef RELEASE_H
+#define RELEASE_H
+
 #include <glib.h>
 
 char * release_get_latest(void);
+
+#endif
diff --git a/src/room_chat.h b/src/room_chat.h
index d455e03c..d62383c9 100644
--- a/src/room_chat.h
+++ b/src/room_chat.h
@@ -20,6 +20,9 @@
  *
  */
 
+#ifndef ROOM_CHAT_H
+#define ROOM_CHAT_H
+
 #include <glib.h>
 
 void room_join(const char * const jid, const char * const nick);
@@ -33,3 +36,5 @@ GList * room_get_roster(const char * const jid);
 void room_set_roster_received(const char * const jid);
 gboolean room_get_roster_received(const char * const jid);
 void room_remove_from_roster(const char * const jid, const char * const nick);
+
+#endif
diff --git a/src/tinyurl.h b/src/tinyurl.h
index 0df9865b..0f40a20d 100644
--- a/src/tinyurl.h
+++ b/src/tinyurl.h
@@ -20,7 +20,12 @@
  *
  */
 
+#ifndef TINYURL_H
+#define TINYURL_H
+
 #include <glib.h>
 
 gboolean tinyurl_valid(char *url);
 char * tinyurl_get(char *url);
+
+#endif
diff --git a/src/ui.h b/src/ui.h
index 84583553..3875ded8 100644
--- a/src/ui.h
+++ b/src/ui.h
@@ -20,8 +20,8 @@
  *
  */
 
-#ifndef WINDOWS_H
-#define WINDOWS_h
+#ifndef UI_H
+#define UI_H
 
 #include "config.h"