diff --git a/deps/rabbitmq_ct_helpers/tools/tls-certs/Makefile b/deps/rabbitmq_ct_helpers/tools/tls-certs/Makefile
index 6f6fec5fd680..5071bedb62da 100644
--- a/deps/rabbitmq_ct_helpers/tools/tls-certs/Makefile
+++ b/deps/rabbitmq_ct_helpers/tools/tls-certs/Makefile
@@ -52,11 +52,11 @@ $(DIR)/testca/cacert.pem:
 $(DIR)/%/cert.pem: $(DIR)/testca/cacert.pem
 	$(gen_verbose) mkdir -p $(DIR)/$(TARGET)
 	$(verbose) { ( cd $(DIR)/$(TARGET) && \
+	    sed -e 's/@HOSTNAME@/$(HOSTNAME)/g' $(CURDIR)/openssl.cnf.in > $(CURDIR)/openssl.cnf && \
 	    openssl genrsa -out key.pem 2048 && \
-	    openssl req -new -key key.pem -out req.pem -outform PEM \
+	    openssl req -config $(CURDIR)/openssl.cnf -new -key key.pem -out req.pem -outform PEM \
 	      -subj /C=UK/ST=England/CN=$(HOSTNAME)/O=$(TARGET)/L=$$$$/ -nodes && \
 	    cd ../testca && \
-	    sed -e 's/@HOSTNAME@/$(HOSTNAME)/g' $(CURDIR)/openssl.cnf.in > $(CURDIR)/openssl.cnf && \
 	    openssl ca -config $(CURDIR)/openssl.cnf -in ../$(TARGET)/req.pem -out \
 	      ../$(TARGET)/cert.pem -notext -batch -extensions \
 	      $(TARGET)_ca_extensions && \