diff --git a/scripts/imgtool.py b/scripts/imgtool.py
index 8a3e233..fb09f96 100755
--- a/scripts/imgtool.py
+++ b/scripts/imgtool.py
@@ -7,9 +7,9 @@
 import sys
 
 def gen_rsa2048(args):
-    keys.RSA2048.generate().export_private(args.keyfile)
+    keys.RSA2048.generate().export_private(args.key)
 def gen_ecdsa_p256(args):
-    keys.ecdsa256p1.generate().export_private(args.keyfile)
+    keys.ecdsa256p1.generate().export_private(args.key)
 def gen_ecdsa_p224(args):
     print("TODO: p-224 not yet implemented")