diff --git a/src/package-manager.coffee b/src/package-manager.coffee
index 5ef0d2a46..6772178af 100644
--- a/src/package-manager.coffee
+++ b/src/package-manager.coffee
@@ -47,6 +47,7 @@ class PackageManager
     @packagesCache = require('../package.json')?._atomPackages ? {}
     @loadedPackages = {}
     @activePackages = {}
+    @activatingPackages = {}
     @packageStates = {}
     @serviceHub = new ServiceHub
 
@@ -437,9 +438,12 @@ class PackageManager
     if pack = @getActivePackage(name)
       Promise.resolve(pack)
     else if pack = @loadPackage(name)
+      @activatingPackages[pack.name] = pack
       pack.activate().then =>
-        @activePackages[pack.name] = pack
-        @emitter.emit 'did-activate-package', pack
+        if @activatingPackages[pack.name]?
+          delete @activatingPackages[pack.name]
+          @activePackages[pack.name] = pack
+          @emitter.emit 'did-activate-package', pack
         pack
     else
       Promise.reject(new Error("Failed to load package '#{name}'"))
@@ -475,6 +479,7 @@ class PackageManager
       @setPackageState(pack.name, state) if state = pack.serialize?()
     pack.deactivate()
     delete @activePackages[pack.name]
+    delete @activatingPackages[pack.name]
     @emitter.emit 'did-deactivate-package', pack
 
   handleMetadataError: (error, packagePath) ->