diff --git a/src/grammar-registry.js b/src/grammar-registry.js
index c1fb33803..b442b4693 100644
--- a/src/grammar-registry.js
+++ b/src/grammar-registry.js
@@ -21,9 +21,15 @@ class GrammarRegistry extends FirstMate.GrammarRegistry {
   constructor ({config} = {}) {
     super({maxTokensPerLine: 100, maxLineLength: 1000})
     this.config = config
+    this.subscriptions = new CompositeDisposable()
+  }
+
+  clear () {
+    super.clear()
+    if (this.subscriptions) this.subscriptions.dispose()
+    this.subscriptions = new CompositeDisposable()
     this.languageNameOverridesByBufferId = new Map()
     this.grammarScoresByBuffer = new Map()
-    this.subscriptions = new CompositeDisposable()
 
     const grammarAddedOrUpdated = this.grammarAddedOrUpdated.bind(this)
     this.onDidAddGrammar(grammarAddedOrUpdated)
diff --git a/src/project.js b/src/project.js
index dec5c4db5..8de92b97e 100644
--- a/src/project.js
+++ b/src/project.js
@@ -2,7 +2,7 @@ const path = require('path')
 
 const _ = require('underscore-plus')
 const fs = require('fs-plus')
-const {Emitter, Disposable} = require('event-kit')
+const {Emitter, Disposable, CompositeDisposable} = require('event-kit')
 const TextBuffer = require('text-buffer')
 const {watchPath} = require('./path-watcher')
 
@@ -37,6 +37,7 @@ class Project extends Model {
     this.watcherPromisesByPath = {}
     this.retiredBufferIDs = new Set()
     this.retiredBufferPaths = new Set()
+    this.subscriptions = new CompositeDisposable()
     this.consumeServices(packageManager)
   }
 
@@ -56,6 +57,9 @@ class Project extends Model {
     this.emitter.dispose()
     this.emitter = new Emitter()
 
+    this.subscriptions.dispose()
+    this.subscriptions = new CompositeDisposable()
+
     for (let buffer of this.buffers) {
       if (buffer != null) buffer.destroy()
     }
@@ -658,7 +662,7 @@ class Project extends Model {
 
   addBuffer (buffer, options = {}) {
     this.buffers.push(buffer)
-    this.grammarRegistry.maintainLanguageMode(buffer)
+    this.subscriptions.add(this.grammarRegistry.maintainLanguageMode(buffer))
     this.subscribeToBuffer(buffer)
     this.emitter.emit('did-add-buffer', buffer)
     return buffer