diff --git a/Makefile b/Makefile
index 523632edc6..63344bd502 100644
--- a/Makefile
+++ b/Makefile
@@ -18,8 +18,9 @@ Build/SysConfig.hs: configure.hs Build/TestConfig.hs Build/Configure.hs
 	if [ "$(CABAL)" = ./Setup ]; then ghc --make Setup; fi
 	$(CABAL) configure --ghc-options="$(shell Build/collect-ghc-options.sh)"
 
+# -j1 is used for reproducible build
 git-annex: Build/SysConfig.hs
-	$(CABAL) build
+	$(CABAL) build -j1
 	ln -sf dist/build/git-annex/git-annex git-annex
 
 man/%.1: doc/%.mdwn
@@ -242,8 +243,7 @@ androidapp:
 	$(MAKE) -C standalone/android
 
 # We bypass cabal, and only run the main ghc --make command for a
-# fast development built. Note: Does not rebuild C libraries, or link
-# executable.
+# fast development built.
 fast: dist/caballog
 	@$$(grep 'ghc --make' dist/caballog | head -n 1 | sed -e 's/-package-id [^ ]*//g' -e 's/-hide-all-packages//') -O0 -j -dynamic
 	@ln -sf dist/build/git-annex/git-annex git-annex
diff --git a/debian/changelog b/debian/changelog
index 451d1b473b..79598575dc 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,9 @@
+git-annex (5.20151117) UNRELEASED; urgency=medium
+
+  * Build with -j1 again to get reproducible build.
+
+ -- Joey Hess <id@joeyh.name>  Mon, 16 Nov 2015 16:49:34 -0400
+
 git-annex (5.20151116) unstable; urgency=medium
 
   * Use concurrent-output library when configured with -fConcurrentOutput.