diff --git a/src/build.py b/src/build.py
index db793c5a1..fc665f57c 100644
--- a/src/build.py
+++ b/src/build.py
@@ -100,7 +100,7 @@ if env['PLATFORM'] == 'Darwin':
     if env['FULL_LIB_PATH']:
         lib_path = '%s/%s' % (env['MAPNIK_LIB_BASE'],mapnik_libname)
     else:
-        lib_path = '@loader_path/'+libmapnik_libname
+        lib_path = '@loader_path/'+mapnik_libname
     mapnik_lib_link_flag += ' -Wl,-install_name,%s' % lib_path
     _d = {'version':env['MAPNIK_VERSION_STRING'].replace('-pre','')}
     mapnik_lib_link_flag += ' -current_version %(version)s -compatibility_version %(version)s' % _d