diff --git a/development/sourcemap-validator.js b/development/sourcemap-validator.js
new file mode 100644
index 000000000..edc97667a
--- /dev/null
+++ b/development/sourcemap-validator.js
@@ -0,0 +1,49 @@
+const fs = require('fs')
+const { SourceMapConsumer } = require('source-map')
+
+//
+// Utility to help check if sourcemaps are working
+//
+// searches `dist/chrome/inpage.js` for "new Error" statements
+// and prints their source lines using the sourcemaps.
+// if not working it may error or print minified garbage
+//
+
+start()
+
+async function start() {
+  const rawBuild = fs.readFileSync(__dirname + '/../dist/chrome/inpage.js', 'utf8')
+  const rawSourceMap = fs.readFileSync(__dirname + '/../dist/sourcemaps/inpage.js.map', 'utf8')
+  const consumer = await new SourceMapConsumer(rawSourceMap)
+
+  console.log('hasContentsOfAllSources:', consumer.hasContentsOfAllSources(), '\n')
+  console.log('sources:')
+  consumer.sources.map((sourcePath) => console.log(sourcePath))
+
+  console.log('\nexamining "new Error" statements:\n')
+  const sourceLines = rawBuild.split('\n')
+  sourceLines.map(line => indicesOf('new Error', line))
+  .forEach((errorIndices, lineIndex) => {
+    // if (errorIndex === null) return console.log('line does not contain "new Error"')
+    errorIndices.forEach((errorIndex) => {
+      const position = { line: lineIndex + 1, column: errorIndex }
+      const result = consumer.originalPositionFor(position)
+      if (!result.source) return console.warn(`!! missing source for position: ${position}`)
+      // filter out deps distributed minified without sourcemaps
+      if (result.source === 'node_modules/browserify/node_modules/browser-pack/_prelude.js') return // minified mess
+      if (result.source === 'node_modules/web3/dist/web3.min.js') return // minified mess
+      const sourceContent = consumer.sourceContentFor(result.source)
+      const sourceLines = sourceContent.split('\n')
+      const line = sourceLines[result.line-1]
+      console.log(`\n========================== ${result.source} ====================================\n`)
+      console.log(line)
+      console.log(`\n==============================================================================\n`)
+    })
+  })
+}
+
+function indicesOf(substring, string) {
+  var a=[],i=-1;
+  while((i=string.indexOf(substring,i+1)) >= 0) a.push(i);
+  return a;
+}
diff --git a/package.json b/package.json
index 953d8d7ac..39182fba0 100644
--- a/package.json
+++ b/package.json
@@ -269,6 +269,7 @@
     "selenium-webdriver": "^3.5.0",
     "shell-parallel": "^1.0.3",
     "sinon": "^5.0.0",
+    "source-map": "^0.7.2",
     "stylelint-config-standard": "^18.2.0",
     "tape": "^4.5.1",
     "testem": "^2.0.0",