diff --git a/Makefile b/Makefile
index fddd13f..eabe38a 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,8 @@
+FEATURES := nightly yolocrypto
 
 doc:
-	cargo rustdoc --features "nightly yolocrypto" -- --html-in-header rustdoc-include-katex-header.html
+	cargo rustdoc --features "$(FEATURES)" -- --html-in-header rustdoc-include-katex-header.html
 
 doc-internal:
-	cargo rustdoc --features "nightly yolocrypto" -- --html-in-header rustdoc-include-katex-header.html --document-private-items
+	cargo rustdoc --features "$(FEATURES)" -- --html-in-header rustdoc-include-katex-header.html --document-private-items