diff --git a/lib/ocaml/src/Makefile b/lib/ocaml/src/Makefile
index 0b989ce..723402b 100644
--- a/lib/ocaml/src/Makefile
+++ b/lib/ocaml/src/Makefile
@@ -1,6 +1,7 @@
-SOURCES = Thrift.ml TBinaryProtocol.ml TSocket.ml TChannelTransport.ml TServer.ml TSimpleServer.ml
+SOURCES = Thrift.ml TBinaryProtocol.ml TSocket.ml TChannelTransport.ml TServer.ml TSimpleServer.ml TServerSocket.ml TThreadedServer.ml
 RESULT = thrift
-LIBS = unix
+LIBS = unix threads
+THREADS = yes
 all: native-code-library byte-code-library top
 OCAMLMAKEFILE = ../OCamlMakefile
 include $(OCAMLMAKEFILE)