diff --git a/tests/unit/Makefile b/tests/unit/Makefile
index 447a5f619..9f1e5c99e 100644
--- a/tests/unit/Makefile
+++ b/tests/unit/Makefile
@@ -1,6 +1,6 @@
 GTESTFLAG := -lgtest -lgtest_main
 RPATH := -Wl,-rpath
-EXTRAFLAGS := -lyosys
+EXTRAFLAGS := -lyosys -pthreads
 
 OBJTEST := objtest
 BINTEST := bintest