diff --git a/tests/data_files/Makefile b/tests/data_files/Makefile
index 257903c..bf61706 100644
--- a/tests/data_files/Makefile
+++ b/tests/data_files/Makefile
@@ -1003,6 +1003,38 @@
 	$(OPENSSL) ec -pubin -in $< -out $@ -conv_form compressed
 all_final += ec_bp512_pub.comp.pem
 
+ec_x25519_prv.der:
+	$(OPENSSL) genpkey -algorithm X25519 -out $@ -outform DER
+all_final += ec_x25519_prv.der
+
+ec_x25519_pub.der: ec_x25519_pub.der
+	$(OPENSSL) pkey -in $< -inform DER -out $@ -outform DER
+all_final += ec_x25519_pub.der
+
+ec_x25519_prv.pem: ec_x25519_prv.pem
+	$(OPENSSL) pkey -in $< -inform DER -out $@
+all_final += ec_x25519_prv.pem
+
+ec_x25519_pub.pem: ec_x25519_pub.pem
+	$(OPENSSL) pkey -in $< -inform DER -out $@
+all_final += ec_x25519_pub.pem
+
+ec_x448_prv.der:
+	$(OPENSSL) genpkey -algorithm X448 -out $@ -outform DER
+all_final += ec_x448_prv.der
+
+ec_x448_pub.der: ec_x448_pub.der
+	$(OPENSSL) pkey -in $< -inform DER -out $@ -outform DER
+all_final += ec_x448_pub.der
+
+ec_x448_prv.pem: ec_x448_prv.pem
+	$(OPENSSL) pkey -in $< -inform DER -out $@
+all_final += ec_x448_prv.pem
+
+ec_x448_pub.pem: ec_x448_pub.pem
+	$(OPENSSL) pkey -in $< -inform DER -out $@
+all_final += ec_x448_pub.pem
+
 ################################################################
 #### Convert PEM keys to DER format
 ################################################################