diff --git a/tests/data_files/Makefile b/tests/data_files/Makefile
index 2bc17fb24b..3d2d5dccd5 100644
--- a/tests/data_files/Makefile
+++ b/tests/data_files/Makefile
@@ -41,8 +41,8 @@ test_ca_key_file_rsa = test-ca.key
 test_ca_pwd_rsa = PolarSSLTest
 test_ca_config_file = test-ca.opensslconf
 
-$(test_ca_key_file_rsa):$(test_ca_pwd_rsa)
-    $(OPENSSL) genrsa -aes-128-cbc -passout pass:$< -out $@ 2048
+$(test_ca_key_file_rsa):
+	$(OPENSSL) genrsa -aes-128-cbc -passout pass:$(test_ca_pwd_rsa) -out $@ 2048
 all_final += $(test_ca_key_file_rsa)
 
 test-ca.req.sha256: $(test_ca_key_file_rsa)