diff --git a/lfs/perl-Device-SerialPort b/lfs/perl-Device-SerialPort
index 37138430e..7f40b5587 100644
--- a/lfs/perl-Device-SerialPort
+++ b/lfs/perl-Device-SerialPort
@@ -70,7 +70,7 @@ $(subst %,%_BLAKE2,$(objects)) :
 $(TARGET) : $(patsubst %,$(DIR_DL)/%,$(objects))
 	@$(PREBUILD)
 	@rm -rf $(DIR_APP) && cd $(DIR_SRC) && tar zxf $(DIR_DL)/$(DL_FILE)
-	cd $(DIR_APP) && perl Makefile.PL
+	cd $(DIR_APP) && perl Makefile.PL TESTPORT=/dev/null
 	cd $(DIR_APP) && make $(MAKETUNING)
 	cd $(DIR_APP) && make install
 	@rm -rf $(DIR_APP)