diff --git a/src/economy.h b/src/economy.h
index b06ed21c3..f07d672e0 100644
--- a/src/economy.h
+++ b/src/economy.h
@@ -37,11 +37,14 @@ extern "C" {
 
 #define TRADE_FRACTION          100
 
-    extern int income(const struct unit *u);
-
 /* Wieviel Fremde eine Partei pro Woche aufnehmen kann */
 #define MAXNEWBIES								5
 
+    struct unit;
+    struct region;
+    struct faction;
+    int income(const struct unit *u);
+
     void economics(struct region *r);
     void produce(struct region *r);
     void auto_work(struct region *r);