diff --git a/src/actions.cpp b/src/actions.cpp
index 471e0070955..b0df585348d 100644
--- a/src/actions.cpp
+++ b/src/actions.cpp
@@ -114,7 +114,10 @@ bool can_recruit_on(const gamemap& map, const gamemap::location& leader, const g
 		return false;
 
 	castle_cost_calculator calc(map);
-	const paths::route& rt = a_star_search(leader, loc, 100.0, &calc, map.w(), map.h());
+	// The limit computed in the third argument is more than enough for
+	// any convex castle on the map. Strictly speaking it could be 
+	// reduced to sqrt(map.w()**2 + map.h()**2).
+	const paths::route& rt = a_star_search(leader, loc, map.w()+map.h(), &calc, map.w(), map.h());
 
 	if(rt.steps.empty())
 		return false;