diff --git a/src/Makevars b/src/Makevars
index 624460b41..a5787c251 100644
--- a/src/Makevars
+++ b/src/Makevars
@@ -1 +1,2 @@
 PKG_CFLAGS = $(C_VISIBILITY) -I../inst/include
+PKG_LIBS = -lpthread