diff --git a/SConstruct b/SConstruct
index e8fe2d84e..67f647272 100644
--- a/SConstruct
+++ b/SConstruct
@@ -1720,7 +1720,7 @@ if not preconfigured:
                         env['SKIPPED_DEPS'].append('proj-min-version')
                     else:
                         env.Append(CPPDEFINES = define)
-                        env.Append(CPPDEFINES = "-DPROJ_VERSION=%d" % version)
+                        env.Append(CPPDEFINES = "-DMAPNIK_PROJ_VERSION=%d" % version)
                 else:
                     env.Append(CPPDEFINES = define)
             else:
diff --git a/include/mapnik/projection.hpp b/include/mapnik/projection.hpp
index ffca994d3..0f0918456 100644
--- a/include/mapnik/projection.hpp
+++ b/include/mapnik/projection.hpp
@@ -39,7 +39,7 @@ MAPNIK_DISABLE_WARNING_POP
 
 
 // fwd decl
-#if PROJ_VERSION >= 80000
+#if MAPNIK_PROJ_VERSION >= 80000
 struct pj_ctx;
 using PJ_CONTEXT = struct pj_ctx;
 #else