diff --git a/include/mapnik/map.hpp b/include/mapnik/map.hpp
index 7b0c155c5..8cb81f5db 100644
--- a/include/mapnik/map.hpp
+++ b/include/mapnik/map.hpp
@@ -103,7 +103,7 @@ private:
     boost::optional<std::string> font_directory_;
     freetype_engine::font_file_mapping_type font_file_mapping_;
     freetype_engine::font_memory_cache_type font_memory_cache_;
-    std::unique_ptr<proj_transform_cache> proj_cache_ = {};
+    std::unique_ptr<proj_transform_cache> proj_cache_;
 public:
     using const_style_iterator = std::map<std::string,feature_type_style>::const_iterator;
     using style_iterator = std::map<std::string,feature_type_style>::iterator;
diff --git a/src/map.cpp b/src/map.cpp
index 8d20225ca..bc7d4d2c4 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -76,7 +76,8 @@ Map::Map()
     extra_params_(),
     font_directory_(),
     font_file_mapping_(),
-    font_memory_cache_() {}
+    font_memory_cache_(),
+    proj_cache_(std::make_unique<proj_transform_cache>()) {}
 
 Map::Map(int width,int height, std::string const& srs)
     : width_(width),
@@ -90,7 +91,8 @@ Map::Map(int width,int height, std::string const& srs)
       extra_params_(),
       font_directory_(),
       font_file_mapping_(),
-      font_memory_cache_() {}
+      font_memory_cache_(),
+      proj_cache_(std::make_unique<proj_transform_cache>()) {}
 
 Map::Map(Map const& rhs)
     : width_(rhs.width_),
@@ -112,7 +114,8 @@ Map::Map(Map const& rhs)
       font_directory_(rhs.font_directory_),
       font_file_mapping_(rhs.font_file_mapping_),
       // on copy discard memory caches
-      font_memory_cache_()
+      font_memory_cache_(),
+      proj_cache_(std::make_unique<proj_transform_cache>())
 {
     init_proj_transforms();
 }