diff --git a/darwin.cmake b/darwin.cmake
index 7574cc1..03149ef 100644
--- a/darwin.cmake
+++ b/darwin.cmake
@@ -17,5 +17,5 @@ set(OPUS_INCLUDE_DIR $ENV{OPUS_INCLUDE})
 set(MP3LAME_LIBRARY $ENV{MP3LAME_LIBS})
 set(MP3LAME_INCLUDE_DIR $ENV{MP3LAME_INCLUDE})
 
-set(MPG123_LIBRARY $ENV{MPG123_LIBS})
-set(MPG123_INCLUDE_DIR $ENV{MPG123_INCLUDE})
+set(mpg123_LIBRARY $ENV{MPG123_LIBS})
+set(mpg123_INCLUDE_DIR $ENV{MPG123_INCLUDE})