diff --git a/include/boost/geometry/strategies/geographic/mapping_ssf.hpp b/include/boost/geometry/strategies/geographic/mapping_ssf.hpp
index 6f52936d6..9ac86db71 100644
--- a/include/boost/geometry/strategies/geographic/mapping_ssf.hpp
+++ b/include/boost/geometry/strategies/geographic/mapping_ssf.hpp
@@ -68,7 +68,7 @@ struct mapper<Spheroid, mapping_reduced, CalculationType>
 
     inline CalculationType map_lat(CalculationType const& lat) const
     {
-        return ::atan(b_div_a * ::tan(lat));
+        return atan(b_div_a * tan(lat));
     }
 
     CalculationType b_div_a;
@@ -87,7 +87,7 @@ struct mapper<Spheroid, mapping_geocentric, CalculationType>
 
     inline CalculationType map_lat(CalculationType const& lat) const
     {
-        return ::atan(sqr_b_div_a * ::tan(lat));
+        return atan(sqr_b_div_a * tan(lat));
     }
 
     CalculationType sqr_b_div_a;