diff --git a/.gitignore b/.gitignore
index 4df9200e..37eb9c33 100644
--- a/.gitignore
+++ b/.gitignore
@@ -19,7 +19,7 @@
 *.swp
 *.save
 
-*.uptodate
+.Makefile.uptodate
 
 protocol/aux/
 protocol/html/
diff --git a/Makefile b/Makefile
index 72883d64..623e1da0 100644
--- a/Makefile
+++ b/Makefile
@@ -3,18 +3,18 @@
 # sudo pip install rst2html5
 
 .PHONY: all all-zips protocol
-all-zips: Makefile.uptodate
+all-zips: .Makefile.uptodate
 	$(MAKE) README.rst
 	$(MAKE) index.html $(addsuffix .html,$(filter-out README,$(basename $(wildcard *.rst))))
 
 all: all-zips protocol
 
-protocol: Makefile.uptodate
+protocol: .Makefile.uptodate
 	$(MAKE) -C protocol
 
-Makefile.uptodate: Makefile
+.Makefile.uptodate: Makefile
 	$(MAKE) clean
-	touch Makefile.uptodate
+	touch .Makefile.uptodate
 
 define PROCESSRST
 $(eval TITLE := $(shell echo '$(basename $<)' | sed -E 's|zip-0{0,3}|ZIP |'): $(shell grep -E '^(\.\.)?\s*Title:' $< |sed -E 's|.*Title:\s*||'))
diff --git a/protocol/Makefile b/protocol/Makefile
index 506684c6..3f3cabeb 100644
--- a/protocol/Makefile
+++ b/protocol/Makefile
@@ -17,15 +17,15 @@ NOCRUFT?=|awk '{gsub(/[({<][/][^ ]* ?/,"")}1' |sed '/name{index:.*} has been ref
 # In this case the updated .pdf will be in the aux/ directory.
 
 .PHONY: all-specs all
-all-specs: Makefile.uptodate
+all-specs: .Makefile.uptodate
 	$(MAKE) nufour.pdf heartwood.pdf blossom.pdf sapling.pdf sprout.pdf
 
-all: Makefile.uptodate
+all: .Makefile.uptodate
 	$(MAKE) nufour heartwood blossom sapling sprout
 
-Makefile.uptodate: Makefile
+.Makefile.uptodate: Makefile
 	$(MAKE) clean
-	touch Makefile.uptodate
+	touch .Makefile.uptodate
 
 sprout.pdf: protocol.tex zcash.bib incremental_merkle.png key_components.png
 	$(MAKE) sprout