diff --git a/lib/runner.js b/lib/runner.js
index f65452d..bf84cc1 100644
--- a/lib/runner.js
+++ b/lib/runner.js
@@ -12,6 +12,7 @@ const Mocha = require('mocha');
 const glob = require('glob');
 const mkdirp = require('mkdirp');
 const tmp = require('tmp');
+const _ = require('lodash');
 
 const fs = require('fs');
 const path = require('path');
@@ -40,6 +41,39 @@ function formatJson(val) {
 	return JSON.stringify(val, null, 2);
 }
 
+function expandError(err) {
+	try {
+		if (!(err instanceof Error)) {
+			return;
+		}
+		const detail = {};
+		// particle-api-js stores the original HTTP client error in a `error` property
+		if (err.error instanceof Error) {
+			detail['cause'] = err.error.toString();
+		}
+		// The parsed body of a 3xx or 4xx response goes to `body` (but only if it's a valid JSON,
+		// otherwise the info is not available)
+		if (err.body !== undefined && !(err.body instanceof Error)) {
+			detail['body'] = err.body;
+		}
+		const lines = [];
+		for (let [name, val] of Object.entries(detail)) { // eslint-disable-line prefer-const
+			if (!_.isString(val)) {
+				val = JSON.stringify(val);
+			}
+			lines.push(name + ': ' + val);
+		}
+		if (lines.length) {
+			if (err.message) {
+				lines.unshift(err.message);
+			}
+			err.message = lines.join('\n\t');
+		}
+	} catch (err) {
+		// Ignore
+	}
+}
+
 class Runner {
 	constructor({ log }) {
 		this._log = log; // Logger instance
@@ -387,18 +421,23 @@ class Runner {
 				test.title = s;
 			}
 		};
+		const testFail = (test, err) => {
+			expandError(err);
+		};
 		const runEnd = () => {
 			runner.off(MochaRunner.constants.EVENT_SUITE_BEGIN, suiteBegin);
 			runner.off(MochaRunner.constants.EVENT_SUITE_END, suiteEnd);
 			runner.off(MochaRunner.constants.EVENT_TEST_BEGIN, testBegin);
 			runner.off(MochaRunner.constants.EVENT_TEST_END, testEnd);
 			runner.off(MochaRunner.constants.EVENT_TEST_PASS, testPass);
+			runner.off(MochaRunner.constants.EVENT_TEST_FAIL, testPass);
 		};
 		runner.on(MochaRunner.constants.EVENT_SUITE_BEGIN, suiteBegin);
 		runner.on(MochaRunner.constants.EVENT_SUITE_END, suiteEnd);
 		runner.on(MochaRunner.constants.EVENT_TEST_BEGIN, testBegin);
 		runner.on(MochaRunner.constants.EVENT_TEST_END, testEnd);
 		runner.prependListener(MochaRunner.constants.EVENT_TEST_PASS, testPass);
+		runner.prependListener(MochaRunner.constants.EVENT_TEST_FAIL, testFail);
 		runner.once(MochaRunner.constants.EVENT_RUN_END, runEnd);
 	}