diff --git a/include/mbgl/map/transform.hpp b/include/mbgl/map/transform.hpp
index 359c325f1..df7839ea9 100644
--- a/include/mbgl/map/transform.hpp
+++ b/include/mbgl/map/transform.hpp
@@ -96,7 +96,7 @@ private:
     const double max_scale = std::pow(2, 18);
 
     // cache values for spherical mercator math
-    double zc, Bc, Cc;
+    double Bc, Cc;
 
     std::forward_list<std::shared_ptr<util::transition>> transitions;
     std::shared_ptr<util::transition> scale_timeout;
diff --git a/src/map/transform.cpp b/src/map/transform.cpp
index 251af30f9..8187bed3e 100644
--- a/src/map/transform.cpp
+++ b/src/map/transform.cpp
@@ -111,7 +111,6 @@ void Transform::setLonLatZoom(const double lon, const double lat, const double z
     double new_scale = std::pow(2.0, zoom);
 
     const double s = new_scale * util::tileSize;
-    zc = s / 2;
     Bc = s / 360;
     Cc = s / (2 * M_PI);
 
@@ -309,7 +308,6 @@ void Transform::_setScaleXY(const double new_scale, const double xn, const doubl
     }
 
     const double s = final.scale * util::tileSize;
-    zc = s / 2;
     Bc = s / 360;
     Cc = s / (2 * M_PI);