diff --git a/pokerth_game.pro b/pokerth_game.pro
index 0c1548b0..04159de9 100644
--- a/pokerth_game.pro
+++ b/pokerth_game.pro
@@ -393,6 +393,7 @@ mac{
 	# make sure you have a universal version of boost
 	LIBS += /usr/local/lib/libboost_thread-mt-1_35.a
 	LIBS += /usr/local/lib/libboost_filesystem-mt-1_35.a
+	LIBS += /usr/local/lib/libboost_system-mt-1_35.a
 	LIBS += /usr/local/lib/libboost_iostreams-mt-1_35.a
 	# libraries installed on every mac
 	LIBS += -lcrypto -lz -lcurl -framework Carbon
diff --git a/pokerth_server.pro b/pokerth_server.pro
index 615746be..059d7e0a 100644
--- a/pokerth_server.pro
+++ b/pokerth_server.pro
@@ -229,6 +229,7 @@ mac{
 	# make sure you have a universal version of boost
 	LIBS += /usr/local/lib/libboost_thread-mt-1_35.a
 	LIBS += /usr/local/lib/libboost_filesystem-mt-1_35.a
+	LIBS += /usr/local/lib/libboost_system-mt-1_35.a
 	LIBS += /usr/local/lib/libboost_iostreams-mt-1_35.a
 	LIBS += /usr/local/lib/libboost_program_options-mt-1_35.a
 	# libraries installed on every mac