diff --git a/include/mapnik/rule.hpp b/include/mapnik/rule.hpp
index f13a6dadc..cbf6a1751 100644
--- a/include/mapnik/rule.hpp
+++ b/include/mapnik/rule.hpp
@@ -174,16 +174,7 @@ public:
 
 private:
 
-    void swap(rule& rhs) throw()
-    {
-        name_=rhs.name_;
-        min_scale_=rhs.min_scale_;
-        max_scale_=rhs.max_scale_;
-        syms_=rhs.syms_;
-        filter_=rhs.filter_;
-        else_filter_=rhs.else_filter_;
-        also_filter_=rhs.also_filter_;
-    }
+    void swap(rule& rhs) throw();
 };
 
 }
diff --git a/src/rule.cpp b/src/rule.cpp
index b7128f431..51074417a 100644
--- a/src/rule.cpp
+++ b/src/rule.cpp
@@ -22,8 +22,12 @@
 
 // mapnik
 #include <mapnik/rule.hpp>
+#include <mapnik/debug.hpp>
 #include <mapnik/raster_colorizer.hpp>
 
+// stl
+#include <limits>
+
 namespace {
 
     struct deepcopy_symbolizer : public boost::static_visitor<>
@@ -133,6 +137,17 @@ bool rule::operator==(rule const& other)
     return  (this == &other);
 }
 
+void rule::swap(rule& rhs) throw()
+{
+    name_=rhs.name_;
+    min_scale_=rhs.min_scale_;
+    max_scale_=rhs.max_scale_;
+    syms_=rhs.syms_;
+    filter_=rhs.filter_;
+    else_filter_=rhs.else_filter_;
+    also_filter_=rhs.also_filter_;
+}
+
 void rule::set_max_scale(double scale)
 {
     max_scale_=scale;