diff --git a/include/mapnik/text/face.hpp b/include/mapnik/text/face.hpp
index 7624aa290..0a4908ff0 100644
--- a/include/mapnik/text/face.hpp
+++ b/include/mapnik/text/face.hpp
@@ -36,7 +36,7 @@ extern "C"
 }
 
 //stl
-#include <map>
+#include <unordered_map>
 #include <memory>
 #include <string>
 #include <vector>
@@ -47,6 +47,7 @@ namespace mapnik
 class font_face : mapnik::noncopyable
 {
 public:
+    using glyph_info_cache_type = std::unordered_map<glyph_index_t, glyph_info>;
     font_face(FT_Face face);
 
     std::string family_name() const
@@ -75,7 +76,7 @@ public:
 
 private:
     FT_Face face_;
-    mutable std::map<glyph_index_t, glyph_info> glyph_info_cache_;
+    mutable glyph_info_cache_type glyph_info_cache_;
     mutable double char_height_;
 };
 using face_ptr = std::shared_ptr<font_face>;
diff --git a/src/text/face.cpp b/src/text/face.cpp
index 11afd18cb..3f57bc89a 100644
--- a/src/text/face.cpp
+++ b/src/text/face.cpp
@@ -64,7 +64,7 @@ bool font_face::set_unscaled_character_sizes()
 bool font_face::glyph_dimensions(glyph_info & glyph) const
 {
     // Check if glyph is already in cache
-    std::map<glyph_index_t, glyph_info>::const_iterator itr;
+    glyph_info_cache_type::const_iterator itr;
     itr = glyph_info_cache_.find(glyph.glyph_index);
     if (itr != glyph_info_cache_.end()) {
         glyph = itr->second;