diff --git a/build/check.sh b/build/check.sh
deleted file mode 100755
index a8d9278406..0000000000
--- a/build/check.sh
+++ /dev/null
@@ -1,24 +0,0 @@
-#!/bin/bash
-#
-# Copyright 2014 Google Inc.
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-dir=$(dirname $0)/..
-
-set -e
-
-"$dir"/build/build.sh
-"$dir"/build/lint.sh
-
-echo "Compiled binary is $(cat "$dir"/shaka-player.compiled.js | wc -c) bytes."
diff --git a/build/checkversion.sh b/build/checkversion.sh
new file mode 100755
index 0000000000..6e1889090d
--- /dev/null
+++ b/build/checkversion.sh
@@ -0,0 +1,70 @@
+#!/bin/bash
+#
+# Copyright 2015 Google Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+dir=$(dirname $0)/..
+. "$dir"/build/lib.sh
+
+set -e
+
+NPM_VERSION=$(
+  grep '"version"' "$dir"/package.json |
+    cut -f 2 -d : | sed -e 's/.*"\(.*\)".*/\1/'
+)
+PLAYER_VERSION=$(
+  grep GIT_VERSION "$dir"/lib/player/player.js | grep goog.define |
+    cut -f 2 -d , | sed -e "s/.*'\\(.*\\)'.*/\\1/"
+)
+CHANGELOG_VERSION=$(
+  grep '##' "$dir"/CHANGELOG.md | head -1 |
+    cut -f 2 -d ' '
+)
+
+rv=0
+
+echo "git version = $GIT_VERSION"
+echo "npm version = $NPM_VERSION"
+echo "player version = $PLAYER_VERSION"
+echo "changelog version = $CHANGELOG_VERSION"
+echo
+
+if echo "$GIT_VERSION" | grep -q dirty; then
+  echo "Git version is dirty!" 1>&2
+  rv=1
+elif echo "$GIT_VERSION" | egrep -q '(-|unknown)'; then
+  echo "Git version is not a tag!" 1>&2
+  rv=1
+elif ! echo "$GIT_VERSION" | grep -q '^v[0-9]\+\.[0-9]\+\.[0-9]\+$'; then
+  echo "Git version is a malformed release version!" 1>&2
+  echo "It should be three ints separated by dots, with a 'v' prepended." 1>&2
+  rv=1
+else
+  if [ "v$NPM_VERSION" != "$GIT_VERSION" ]; then
+    echo "NPM version does not match git version!" 1>&2
+    rv=1
+  fi
+
+  if [ "$PLAYER_VERSION" != "$GIT_VERSION-debug" ]; then
+    echo "Player version does not match git version!" 1>&2
+    rv=1
+  fi
+
+  if [ "v$CHANGELOG_VERSION" != "$GIT_VERSION" ]; then
+    echo "Changelog version does not match git version!" 1>&2
+    rv=1
+  fi
+fi
+
+exit $rv
diff --git a/build/lib.sh b/build/lib.sh
index 0b5f6c6c38..f0c68eb3dd 100644
--- a/build/lib.sh
+++ b/build/lib.sh
@@ -14,6 +14,8 @@
 
 dir=$(dirname $0)/..
 
+GIT_VERSION=$(cd "$dir"; git describe --tags --dirty || echo unknown)
+
 closure_opts="
   --language_in ECMASCRIPT5
   --language_out ECMASCRIPT5
@@ -56,7 +58,7 @@ closure_opts="
   -D goog.ENABLE_DEBUG_LOADER=false
   -D shaka.asserts.ENABLE_ASSERTS=false
   -D shaka.log.MAX_LOG_LEVEL=0
-  -D GIT_VERSION='$(cd "$dir"; git describe --tags --dirty || echo unknown)'
+  -D GIT_VERSION='$GIT_VERSION'
 "
 
 set -e
diff --git a/package.json b/package.json
index a8f9737574..d3f97eb409 100644
--- a/package.json
+++ b/package.json
@@ -25,6 +25,6 @@
     }
   ],
   "scripts": {
-    "prepublish": "./build/all.sh"
+    "prepublish": "./build/checkversion.sh && ./build/all.sh"
   }
 }
diff --git a/tutorials/dev.html b/tutorials/dev.html
index e2f5d80414..3d3170d7b5 100644
--- a/tutorials/dev.html
+++ b/tutorials/dev.html
@@ -168,7 +168,6 @@ <h3 class="tutorial-heading">
           shaka-player.compiled.js</li>
       <li>gendeps.sh - computes dependencies for running non-compiled code</li>
       <li>lint.sh - checks the code for style issues</li>
-      <li>check.sh - combination of build.sh and lint.sh</li>
       <li>all.sh - combination of gendeps.sh, build.sh, and lint.sh</li>
       <li>docs.sh - generate documentation</li>
     </ul>