diff --git a/s390x/Makefile b/s390x/Makefile
index ddc0969..8603a52 100644
--- a/s390x/Makefile
+++ b/s390x/Makefile
@@ -197,33 +197,27 @@
 %.bin: %.elf
 	$(OBJCOPY) -O binary  $< $@
 
-# Will only be filled when dump has been enabled
-GENPROTIMG_COMM_KEY =
-# allow PCKMO
-genprotimg_pcf = 0x000000e0
-
-ifeq ($(CONFIG_DUMP),yes)
-	# The genprotimg arguments for the cck changed over time so we need to
-	# figure out which argument to use in order to set the cck
-	GENPROTIMG_HAS_COMM_KEY = $(shell $(GENPROTIMG) --help | grep -q -- --comm-key && echo yes)
-	ifeq ($(GENPROTIMG_HAS_COMM_KEY),yes)
-		GENPROTIMG_COMM_KEY = --comm-key $(comm-key)
-	else
-		GENPROTIMG_COMM_KEY = --x-comm-key $(comm-key)
-	endif
-
-	# allow dumping + PCKMO
-	genprotimg_pcf = 0x200000e0
+# The genprotimg arguments for the cck changed over time so we need to
+# figure out which argument to use in order to set the cck
+GENPROTIMG_HAS_COMM_KEY = $(shell $(GENPROTIMG) --help | grep -q -- --comm-key && echo yes)
+ifeq ($(GENPROTIMG_HAS_COMM_KEY),yes)
+	GENPROTIMG_COMM_OPTION := --comm-key
+else
+	GENPROTIMG_COMM_OPTION := --x-comm-key
 endif
 
-# use x-pcf to be compatible with old genprotimg versions
-genprotimg_args = --host-key-document $(HOST_KEY_DOCUMENT) --no-verify $(GENPROTIMG_COMM_KEY) --x-pcf $(genprotimg_pcf)
+ifeq ($(CONFIG_DUMP),yes)
+	# allow dumping + PCKMO
+	GENPROTIMG_PCF := 0x200000e0
+else
+	# allow PCKMO
+	GENPROTIMG_PCF := 0x000000e0
+endif
 
-%selftest.pv.bin: %selftest.bin $(HOST_KEY_DOCUMENT) $(patsubst %.pv.bin,%.parmfile,$@) $(comm-key)
-	$(GENPROTIMG) $(genprotimg_args) --parmfile $(patsubst %.pv.bin,%.parmfile,$@) --image $< -o $@
-
+$(patsubst %.parmfile,%.pv.bin,$(wildcard s390x/*.parmfile)): %.pv.bin: %.parmfile
 %.pv.bin: %.bin $(HOST_KEY_DOCUMENT) $(comm-key)
-	$(GENPROTIMG) $(genprotimg_args) --image $< -o $@
+	$(eval parmfile_args = $(if $(filter %.parmfile,$^),--parmfile $(filter %.parmfile,$^),))
+	$(GENPROTIMG) --host-key-document $(HOST_KEY_DOCUMENT) --no-verify $(GENPROTIMG_COMM_OPTION) $(comm-key) --x-pcf $(GENPROTIMG_PCF) $(parmfile_args) --image $(filter %.bin,$^) -o $@
 
 $(snippet_asmlib): $$(patsubst %.o,%.S,$$@) $(asm-offsets)
 	$(CC) $(CFLAGS) -c -nostdlib -o $@ $<