diff --git a/certs/Makefile b/certs/Makefile
index 9486ed924731..799ad7b9e68a 100644
--- a/certs/Makefile
+++ b/certs/Makefile
@@ -23,8 +23,8 @@ $(obj)/blacklist_hash_list: $(CONFIG_SYSTEM_BLACKLIST_HASH_LIST) FORCE
 targets += blacklist_hash_list
 
 quiet_cmd_extract_certs  = CERT    $@
-      cmd_extract_certs  = $(obj)/extract-cert $(extract-cert-in) $@
-extract-cert-in = $(or $(filter-out $(obj)/extract-cert, $(real-prereqs)),"")
+      cmd_extract_certs  = $(obj)/extract-cert "$(extract-cert-in)" $@
+extract-cert-in = $(filter-out $(obj)/extract-cert, $(real-prereqs))
 
 $(obj)/system_certificates.o: $(obj)/x509_certificate_list
 
diff --git a/scripts/Makefile.modinst b/scripts/Makefile.modinst
index 836391e5d209..4815a8e32227 100644
--- a/scripts/Makefile.modinst
+++ b/scripts/Makefile.modinst
@@ -66,9 +66,13 @@ endif
 # Don't stop modules_install even if we can't sign external modules.
 #
 ifeq ($(CONFIG_MODULE_SIG_ALL),y)
+ifeq ($(filter pkcs11:%, $(CONFIG_MODULE_SIG_KEY)),)
 sig-key := $(if $(wildcard $(CONFIG_MODULE_SIG_KEY)),,$(srctree)/)$(CONFIG_MODULE_SIG_KEY)
+else
+sig-key := $(CONFIG_MODULE_SIG_KEY)
+endif
 quiet_cmd_sign = SIGN    $@
-      cmd_sign = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) $(sig-key) certs/signing_key.x509 $@ \
+      cmd_sign = scripts/sign-file $(CONFIG_MODULE_SIG_HASH) "$(sig-key)" certs/signing_key.x509 $@ \
                  $(if $(KBUILD_EXTMOD),|| true)
 else
 quiet_cmd_sign :=