diff --git a/Makefile.am b/Makefile.am
index eabeea6128..c23bfa5fb1 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -43,6 +43,7 @@ avocado_SOURCES = \
 	Basics/json.c \
 	Basics/locks-macos.c \
 	Basics/locks-posix.c \
+	Basics/locks-macos.c \
 	Basics/Logger.cpp \
 	Basics/LoggerData.cpp \
 	Basics/LoggerInfo.cpp \