diff --git a/lib/bundler/injector.rb b/lib/bundler/injector.rb
index 0eae0c6ece3..1bb29f0b367 100644
--- a/lib/bundler/injector.rb
+++ b/lib/bundler/injector.rb
@@ -107,7 +107,7 @@ def build_gem_lines(conservative_versioning)
         end
 
         if d.groups != Array(:default)
-          group = d.groups.size == 1 ? ", :group => #{d.groups.inspect}" : ", :groups => #{d.groups.inspect}"
+          group = d.groups.size == 1 ? ", :group => #{d.groups.first.inspect}" : ", :groups => #{d.groups.inspect}"
         end
 
         source = ", :source => \"#{d.source}\"" unless d.source.nil?
diff --git a/spec/commands/add_spec.rb b/spec/commands/add_spec.rb
index 2e9ef6b923c..9f11adbcf80 100644
--- a/spec/commands/add_spec.rb
+++ b/spec/commands/add_spec.rb
@@ -69,7 +69,7 @@
   describe "with --group" do
     it "adds dependency for the specified group" do
       bundle "add 'foo' --group='development'"
-      expect(bundled_app("Gemfile").read).to match(/gem "foo", "~> 2.0", :group => \[:development\]/)
+      expect(bundled_app("Gemfile").read).to match(/gem "foo", "~> 2.0", :group => :development/)
       expect(the_bundle).to include_gems "foo 2.0"
     end
 
@@ -100,7 +100,7 @@
 
   it "using combination of short form options works like long form" do
     bundle "add 'foo' -s='file://#{gem_repo2}' -g='development' -v='~>1.0'"
-    expect(bundled_app("Gemfile").read).to include %(gem "foo", "~> 1.0", :group => [:development], :source => "file://#{gem_repo2}")
+    expect(bundled_app("Gemfile").read).to include %(gem "foo", "~> 1.0", :group => :development, :source => "file://#{gem_repo2}")
     expect(the_bundle).to include_gems "foo 1.1"
   end
 
diff --git a/spec/commands/inject_spec.rb b/spec/commands/inject_spec.rb
index 6c1994b59d6..b7ffc89a341 100644
--- a/spec/commands/inject_spec.rb
+++ b/spec/commands/inject_spec.rb
@@ -64,7 +64,7 @@
     it "add gem with group option in gemfile" do
       bundle "inject 'rack-obama' '>0' --group=development"
       gemfile = bundled_app("Gemfile").read
-      str = "gem \"rack-obama\", \"> 0\", :group => [:development]"
+      str = "gem \"rack-obama\", \"> 0\", :group => :development"
       expect(gemfile).to include str
     end