diff --git a/Source/doom.cpp b/Source/doom.cpp
index b7250830b..40093fc54 100644
--- a/Source/doom.cpp
+++ b/Source/doom.cpp
@@ -40,10 +40,22 @@ int doom_get_frame_from_time()
 	return DoomQuestState / 1200;
 }
 
+void doom_cleanup()
+{
+#ifdef HELLFIRE
+	if (pDoomCel != NULL) {
+		MemFreeDbg(pDoomCel);
+		pDoomCel = NULL;
+	}
+#else
+	MemFreeDbg(pDoomCel);
+#endif
+}
+
 #ifdef HELLFIRE
-BOOLEAN doom_alloc_cel()
+static BOOLEAN doom_alloc_cel()
 #else
-void doom_alloc_cel()
+static void doom_alloc_cel()
 #endif
 {
 #ifdef HELLFIRE
@@ -55,22 +67,10 @@ void doom_alloc_cel()
 #endif
 }
 
-void doom_cleanup()
-{
-#ifdef HELLFIRE
-	if (pDoomCel != NULL) {
-		MemFreeDbg(pDoomCel);
-		pDoomCel = NULL;
-	}
-#else
-	MemFreeDbg(pDoomCel);
-#endif
-}
-
 #ifdef HELLFIRE
-BOOLEAN doom_load_graphics()
+static BOOLEAN doom_load_graphics()
 #else
-void doom_load_graphics()
+static void doom_load_graphics()
 #endif
 {
 #ifdef HELLFIRE
diff --git a/Source/doom.h b/Source/doom.h
index 4dbf96b8a..ddb144d17 100644
--- a/Source/doom.h
+++ b/Source/doom.h
@@ -6,26 +6,9 @@
 #ifndef __DOOM_H__
 #define __DOOM_H__
 
-extern int doom_quest_time;
-extern int doom_stars_drawn;
-extern BYTE *pDoomCel;
 extern DIABOOL doomflag;
 extern int DoomQuestState;
 
-/*
-void doom_reset_state();
-void doom_play_movie();
-*/
-int doom_get_frame_from_time();
-#ifdef HELLFIRE
-BOOLEAN doom_alloc_cel();
-void doom_cleanup();
-BOOLEAN doom_load_graphics();
-#else
-void doom_alloc_cel();
-void doom_cleanup();
-void doom_load_graphics();
-#endif
 void doom_init();
 void doom_close();
 void doom_draw();