diff --git a/ppl2/include/ppl_projection.hpp b/ppl2/include/ppl_projection.hpp
index 3db22a8..e06c4f1 100755
--- a/ppl2/include/ppl_projection.hpp
+++ b/ppl2/include/ppl_projection.hpp
@@ -160,7 +160,7 @@ template< typename P_TYPE> class point_projection
     }
 
 
-#ifdef PLL_EXTERNAL_TRACK_LOADING
+#ifdef PPL_EXTERNAL_TRACK_LOADING
 
     uint64_t num_of_p(char *addr, const uint64_t& len){