diff -u -r freetype-2.5.4/src/truetype/ttobjs.c freetype-2.5.4-env/src/truetype/ttobjs.c
--- freetype-2.5.4/src/truetype/ttobjs.c	2014-12-06 18:52:13.098214719 +0100
+++ freetype-2.5.4-env/src/truetype/ttobjs.c	2014-12-10 09:13:04.418886699 +0100
@@ -1264,10 +1264,11 @@
       return FT_THROW( Could_Not_Find_Context );
 
 #ifdef TT_CONFIG_OPTION_SUBPIXEL_HINTING
-    driver->interpreter_version = TT_INTERPRETER_VERSION_38;
-#else
-    driver->interpreter_version = TT_INTERPRETER_VERSION_35;
+    if ( getenv( "FT2_SUBPIXEL_HINTING" ) )
+      driver->interpreter_version = TT_INTERPRETER_VERSION_38;
+    else
 #endif
+      driver->interpreter_version = TT_INTERPRETER_VERSION_35;
 
 #else /* !TT_USE_BYTECODE_INTERPRETER */