diff --git a/.gitignore b/.gitignore
index 38ff8a7b..f3fbff37 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,5 @@
 .DS_Store
-/assets
+/assets/ca.crt
 /state
 /bin
 /build
diff --git a/Makefile.docker b/Makefile.docker
index dfa4578a..067aa0e3 100644
--- a/Makefile.docker
+++ b/Makefile.docker
@@ -26,7 +26,8 @@ $(DIST)/artifacts/vmlinuz: $(BUILD)/kernel/
 
 
 $(BUILD)/kernel/:
-	mkdir -p $@ && curl -L "$(COMPILED_KERNEL_URL)" | tar -xzf - -C $@ --strip=0
+	mkdir -p $@
+	([ -e "$(COMPILED_KERNEL_URL)" ] && cat "$(COMPILED_KERNEL_URL)" || curl -L "$(COMPILED_KERNEL_URL)") | tar -xzf - -C $@
 
 
 $(BUILD)/images.tar: bin/rancheros