-$(obj)/signing_key.x509: $(X509_DEP) $(obj)/extract-cert FORCE
- $(call if_changed,extract_certs,$(if $(CONFIG_MODULE_SIG_KEY),$(if $(X509_DEP),$<,$(CONFIG_MODULE_SIG_KEY)),""))
-endif # CONFIG_MODULE_SIG
+PKCS11_URI := $(filter pkcs11:%, $(CONFIG_MODULE_SIG_KEY))
+ifdef PKCS11_URI
+$(obj)/signing_key.x509: extract-cert-in := $(PKCS11_URI)
+endif
+
+$(obj)/signing_key.x509: $(filter-out $(PKCS11_URI),$(CONFIG_MODULE_SIG_KEY)) $(obj)/extract-cert FORCE
+ $(call if_changed,extract_certs)