diff --git a/src/Makevars.win b/src/Makevars.win
index da255931..aebb1042 100644
--- a/src/Makevars.win
+++ b/src/Makevars.win
@@ -4,7 +4,7 @@ TARGET = lib$(subst gcc,,$(COMPILED_BY))$(R_ARCH)
 PKG_LIBS = \
 	-L$(RWINLIB)/$(TARGET) \
 	-L$(RWINLIB)/lib \
-	-lwinhttp -lcurl -lnghttp2 -lssh2 -lz -lssl -lcrypto -lgdi32 -lws2_32 -lcrypt32 -lbcrypt -lwldap32
+	-lwinhttp -lcurl -lnghttp2 -lssh2 -lz -lssl -lcrypto -pthread -lgdi32 -lws2_32 -lcrypt32 -lbcrypt -lwldap32
 
 PKG_CPPFLAGS= \
 	-I$(RWINLIB)/include -DCURL_STATICLIB -DSTRICT_R_HEADERS