diff --git a/makefile b/makefile
index 44f6f85..ff7e8f5 100644
--- a/makefile
+++ b/makefile
@@ -12,7 +12,7 @@
 IMAGES_BIN = $(patsubst %,%.bin,$(IMAGES))
 IMAGES_LOAD = $(patsubst %,%.load,$(IMAGES))
 
-.PHONY: all images clean init gc #$(IMAGES_LOAD)
+.PHONY: all images clean init gc update #$(IMAGES_LOAD)
 
 all: images
 
@@ -30,6 +30,9 @@
 init:
 	$(NIX_DOCKER_MAINT) sh -c 'nix-env -iA nixpkgs.rsync && rsync --info=progress2 -a /nix/ /nix2/'
 
+update:
+	$(NIX_DOCKER) sh -c 'nix-channel --update'
+
 # Builds and loads all known Docker images.
 images: $(IMAGES_LOAD)