diff --git a/src/common/kernel/battle.c b/src/common/kernel/battle.c
index 03d511d7b..ad43ca124 100644
--- a/src/common/kernel/battle.c
+++ b/src/common/kernel/battle.c
@@ -3505,7 +3505,7 @@ join_allies(battle * b)
       }
     }
 
-    for (sa=s+1;sa!=b->sides+b->nsides;sa=++sa) {
+    for (sa=s+1;sa!=b->sides+b->nsides;++sa) {
       if (enemy(s, sa)) continue;
       if (friendly(s, sa)) continue;
       if (!alliedgroup(r->planep, f, sa->faction, f->allies, HELP_FIGHT)) continue;