diff --git a/install-package.js b/install-package.js
index 9c8bb06..cdfa19b 100644
--- a/install-package.js
+++ b/install-package.js
@@ -3,7 +3,6 @@
 const toPlainObject       = require("es5-ext/object/normalize-options")
     , ensureString        = require("es5-ext/object/validate-stringifiable-value")
     , ee                  = require("event-emitter")
-    , unifyEmitters       = require("event-emitter/unify")
     , ensureConfiguration = require("./lib/private/ensure-user-configuration")
     , createProgressData  = require("./lib/private/create-progress-data")
     , installPackage      = require("./lib/private/install-package");
@@ -16,6 +15,6 @@ module.exports = (name, configuration, options = {}) => {
 			toPlainObject(options), progressData
 		)
 	);
-	unifyEmitters(progressData, promise);
+	promise.progressData = progressData;
 	return promise;
 };
diff --git a/install.js b/install.js
index 6daa0ed..cc191d6 100644
--- a/install.js
+++ b/install.js
@@ -3,7 +3,6 @@
 const toPlainObject       = require("es5-ext/object/normalize-options")
     , ensureString        = require("es5-ext/object/validate-stringifiable-value")
     , ee                  = require("event-emitter")
-    , unifyEmitters       = require("event-emitter/unify")
     , { resolve }         = require("path")
     , ensureConfiguration = require("./lib/private/ensure-user-configuration")
     , createProgressData  = require("./lib/private/create-progress-data")
@@ -15,6 +14,6 @@ module.exports = (path, configuration, options = {}) => {
 	const promise = ee(
 		install({ path }, ensureConfiguration(configuration), toPlainObject(options), progressData)
 	);
-	unifyEmitters(progressData, promise);
+	promise.progressData = progressData;
 	return promise;
 };
diff --git a/lib/private/cli/index.js b/lib/private/cli/index.js
index c0528f9..5b79e6f 100644
--- a/lib/private/cli/index.js
+++ b/lib/private/cli/index.js
@@ -21,6 +21,7 @@ module.exports = async (command, packageName, inputOptions) => {
 			? installPackage(packageName, userConfiguration, inputOptions)
 			: install(process.cwd(), userConfiguration, inputOptions);
 	})();
+	const { progressData } = installPromise;
 	const installsInProgress = new Map();
 
 	const logWordForms = {
@@ -34,11 +35,11 @@ module.exports = async (command, packageName, inputOptions) => {
 			)
 		);
 	};
-	installPromise.on("start", event => {
+	progressData.on("start", event => {
 		installsInProgress.set(event.name, event);
 		updateProgress();
 	});
-	installPromise.on("end", ({ name: endedPackageName }) => {
+	progressData.on("end", ({ name: endedPackageName }) => {
 		const { progressData: { type } } = installsInProgress.get(endedPackageName);
 		installsInProgress.delete(endedPackageName);
 		log.notice(`${ logWordForms.past[type] } %s`, endedPackageName);
diff --git a/update-all.js b/update-all.js
index 1cfc001..365b118 100644
--- a/update-all.js
+++ b/update-all.js
@@ -2,7 +2,6 @@
 
 const toPlainObject       = require("es5-ext/object/normalize-options")
     , ee                  = require("event-emitter")
-    , unifyEmitters       = require("event-emitter/unify")
     , ensureConfiguration = require("./lib/private/ensure-user-configuration")
     , createProgressData  = require("./lib/private/create-progress-data")
     , updateAll           = require("./lib/private/update-all");
@@ -12,6 +11,6 @@ module.exports = (configuration, options = {}) => {
 	const promise = ee(
 		updateAll(ensureConfiguration(configuration), toPlainObject(options), progressData)
 	);
-	unifyEmitters(progressData, promise);
+	promise.progressData = progressData;
 	return promise;
 };