diff --git a/libraries/libmdb/Makefile b/libraries/libmdb/Makefile
index 1fde58889c..796be078d4 100644
--- a/libraries/libmdb/Makefile
+++ b/libraries/libmdb/Makefile
@@ -19,7 +19,7 @@ libmdb.a:	mdb.o midl.o
 	ar rs $@ mdb.o midl.o
 
 libmdb.so:	mdb.o midl.o
-	gcc -shared -o $@ mdb.o midl.o $(SOLIBS)
+	gcc -pthread -shared -o $@ mdb.o midl.o $(SOLIBS)
 
 mdb_stat: mdb_stat.o libmdb.a
 mtest:    mtest.o    libmdb.a