diff --git a/CHANGELOG.md b/CHANGELOG.md
new file mode 100644
index 000000000..720f85dab
--- /dev/null
+++ b/CHANGELOG.md
@@ -0,0 +1,6 @@
+# Changelog
+
+## [Unreleased]
+### Changed
+- Versions are now for the whole of dapptools, rather than per-tool.
+Accordingly, the old CHANGELOG files are superseded by this one.
diff --git a/VERSION b/VERSION
new file mode 100644
index 000000000..d00491fd7
--- /dev/null
+++ b/VERSION
@@ -0,0 +1 @@
+1
diff --git a/nix/solc-updates.md b/nix/solc-updates.md
index 9dea41550..ae7c1039f 100644
--- a/nix/solc-updates.md
+++ b/nix/solc-updates.md
@@ -15,7 +15,7 @@
         1. add a new `solc_X.Y.Z` in the `unreleased` section
         1. update `rev` and `sha256` based on the output from `nix-prefetch-git
            git@github.com:dapphub/nixpkgs refs/heads/solc-X.Y.Z`
-    1. bump the version number in `dapp---version`, `src/dapp/default.nix` and the changelog
+    1. bump the version number in `VERSION` and populate the changelog
     1. commit the changes
 1. open a pr from `dapphub/dapptools:solc-X.Y.Z` to `dapphub/dapptools:master`
 1. once merged tag the commit with the new version number
diff --git a/src/seth/default.nix b/src/seth/default.nix
index f99c9e7b4..2ece3e04a 100644
--- a/src/seth/default.nix
+++ b/src/seth/default.nix
@@ -3,7 +3,7 @@
 
 stdenv.mkDerivation rec {
   name = "seth-${version}";
-  version = "0.8.4";
+  version = lib.fileContents ../../VERSION;
   src = ./.;
 
   nativeBuildInputs = [makeWrapper];
@@ -18,6 +18,10 @@ stdenv.mkDerivation rec {
         else ""}
   '';
 
+  postFixup = ''
+    sed -i s/VERSION_PLACEHOLDER/${version}/ $out/libexec/seth/seth---version
+  '';
+
   meta = {
     description = "Command-line client for talking to Ethereum nodes";
     homepage = https://github.com/dapphub/dapptools/src/seth/;
diff --git a/src/seth/libexec/seth/seth---version b/src/seth/libexec/seth/seth---version
index 1153d72c1..43231e1e7 100755
--- a/src/seth/libexec/seth/seth---version
+++ b/src/seth/libexec/seth/seth---version
@@ -1,8 +1,8 @@
 #!/usr/bin/env bash
-cat <<.
-seth 0.8.4
+cat <<EOF
+seth VERSION_PLACEHOLDER
 Copyright (C) 2016, 2017  Daniel Brockman <daniel@dapphub.com>
 License: GNU GPL version 3 or later <https://gnu.org/licenses/gpl>.
 This is free software: you are free to change and redistribute it.
 There is NO WARRANTY, to the extent permitted by law.
-.
+EOF