diff --git a/server/maphand.cpp b/server/maphand.cpp
index 23b0d2d556..1e3f29d7e5 100644
--- a/server/maphand.cpp
+++ b/server/maphand.cpp
@@ -199,13 +199,7 @@ void climate_change(bool warming, int effect)
       update_tile_knowledge(ptile);
 
       // Check the unit activities.
-      unit_list_iterate(ptile->units, punit)
-      {
-        if (!can_unit_continue_current_activity(punit)) {
-          unit_activity_handling(punit, ACTIVITY_IDLE);
-        }
-      }
-      unit_list_iterate_end;
+      unit_activities_cancel_all_illegal_area(ptile);
     } else if (old == tnew) {
       // This counts toward a climate change although nothing is changed.
       effect--;
diff --git a/server/srv_main.cpp b/server/srv_main.cpp
index b1b8a05319..423e41339a 100644
--- a/server/srv_main.cpp
+++ b/server/srv_main.cpp
@@ -1712,12 +1712,7 @@ void end_turn()
 
         /* Unit activities at the target tile and its neighbors may now
          * be illegal because of present reqs. */
-        unit_activities_cancel_all_illegal(ptile);
-        adjc_iterate(&(wld.map), ptile, n_tile)
-        {
-          unit_activities_cancel_all_illegal(n_tile);
-        }
-        adjc_iterate_end;
+        unit_activities_cancel_all_illegal_area(ptile);
       }
     }
     whole_map_iterate_end;
@@ -1747,12 +1742,7 @@ void end_turn()
 
         /* Unit activities at the target tile and its neighbors may now
          * be illegal because of !present reqs. */
-        unit_activities_cancel_all_illegal(ptile);
-        adjc_iterate(&(wld.map), ptile, n_tile)
-        {
-          unit_activities_cancel_all_illegal(n_tile);
-        }
-        adjc_iterate_end;
+        unit_activities_cancel_all_illegal_area(ptile);
       }
     }
     whole_map_iterate_end;
diff --git a/server/unittools.cpp b/server/unittools.cpp
index 819c4c72d1..e8a94487bc 100644
--- a/server/unittools.cpp
+++ b/server/unittools.cpp
@@ -792,6 +792,22 @@ void unit_activities_cancel_all_illegal(const struct tile *ptile)
   unit_list_iterate_end;
 }
 
+/**
+ * Cancel all illegal activities done by units at the specified tile,
+ * and surrounding tiles. For most rulesets this is for cancelling
+ * irrigation on surrounding tiles when the central tile was the only
+ * source of water, but does not provide water any more.
+ */
+void unit_activities_cancel_all_illegal_area(const struct tile *ptile)
+{
+  unit_activities_cancel_all_illegal(ptile);
+  adjc_iterate(&wld.map, ptile, ptile2)
+  {
+    unit_activities_cancel_all_illegal(ptile2);
+  }
+  adjc_iterate_end;
+}
+
 /**
    Progress settlers in their current tasks,
    and units that is pillaging.
@@ -934,21 +950,10 @@ static void unit_activity_complete(struct unit *punit)
       unit_list_iterate_end;
     }
 
-    tile_changing_activities_iterate(act)
-    {
-      if (act == activity) {
-        /* Some units nearby may not be able to continue their action,
-         * such as building irrigation if we removed the only source
-         * of water from them. */
-        adjc_iterate(&(wld.map), ptile, ptile2)
-        {
-          unit_activities_cancel_all_illegal(ptile2);
-        }
-        adjc_iterate_end;
-        break;
-      }
-    }
-    tile_changing_activities_iterate_end;
+    // Some units nearby may not be able to continue their action,
+    // such as building irrigation if we removed the only source
+    // of water from them.
+    unit_activities_cancel_all_illegal_area(ptile);
   }
 
   if (activity == ACTIVITY_FORTIFYING) {
diff --git a/server/unittools.h b/server/unittools.h
index 585c1d2506..6f78efcb86 100644
--- a/server/unittools.h
+++ b/server/unittools.h
@@ -171,6 +171,7 @@ void unit_did_action(struct unit *punit);
 bool unit_can_be_retired(struct unit *punit);
 
 void unit_activities_cancel_all_illegal(const struct tile *ptile);
+void unit_activities_cancel_all_illegal_area(const struct tile *ptile);
 
 void unit_get_goods(struct unit *punit);