diff --git a/tests/data_files/Makefile b/tests/data_files/Makefile
index c008030..257903c 100644
--- a/tests/data_files/Makefile
+++ b/tests/data_files/Makefile
@@ -935,8 +935,9 @@
 	$(OPENSSL) pkey -in $< -inform DER -out $@
 all_final += ec_prv.pk8param.pem
 
-ec_pub.der: ec_prv.sec1.der
-	$(OPENSSL) pkey -in $< -inform DER -outform DER -pubout -out $@
+ec_pub.pem: ec_prv.sec1.der
+	$(OPENSSL) pkey -in $< -inform DER -outform PEM -pubout -out $@
+all_final += ec_pub.pem
 
 ec_prv.sec1.comp.pem: ec_prv.sec1.pem
 	$(OPENSSL) ec -in $< -out $@ -conv_form compressed