diff --git a/ChangeLog.md b/ChangeLog.md
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,5 +1,9 @@
 # Changelog for dhall-fly
 
+## 0.2.1
+
+* Groups retain the order they are in list of grouped jobs
+
 ## 0.2.0
 
 * Tested with dhall-concourse 0.5.0
diff --git a/dhall-fly.cabal b/dhall-fly.cabal
--- a/dhall-fly.cabal
+++ b/dhall-fly.cabal
@@ -4,10 +4,10 @@
 --
 -- see: https://github.com/sol/hpack
 --
--- hash: fb42954e64638266e0514c8cb46537461e36d17e1295f1d60bc2f2b48dbbf23b
+-- hash: 124eab9f2a66b1fb1fe7643b0e3a4b7084264c70a29698980ec92909df051cdb
 
 name:           dhall-fly
-version:        0.2.0
+version:        0.2.1
 synopsis:       Translate concourse config from Dhall to YAML
 description:    Please see the README on GitHub at <https://github.com/akshaymankar/dhall-fly#readme>
 category:       Concourse, YAML, JSON, Dhall
@@ -159,6 +159,7 @@
     , base >=4.7 && <5
     , dhall >=1.27.0 && <1.28
     , optparse-applicative
+    , ordered-containers >=0.2.2
     , scientific >=0.3.6.2
     , text >=1.2.3.1
     , transformers >=0.5.6.2
@@ -183,6 +184,7 @@
     , dhall-fly
     , dhall-json >=1.5.0 && <1.6
     , optparse-applicative
+    , ordered-containers >=0.2.2
     , scientific >=0.3.6.2
     , text >=1.2.3.1
     , transformers >=0.5.6.2
@@ -210,6 +212,7 @@
     , dhall-fly
     , hspec
     , optparse-applicative
+    , ordered-containers >=0.2.2
     , scientific >=0.3.6.2
     , text >=1.2.3.1
     , transformers >=0.5.6.2
diff --git a/src/Fly/Yaml.hs b/src/Fly/Yaml.hs
--- a/src/Fly/Yaml.hs
+++ b/src/Fly/Yaml.hs
@@ -10,6 +10,7 @@
 import Fly.Types
 
 import qualified Data.HashMap.Strict as HM
+import qualified Data.Map.Ordered as OM
 
 jobsToValue :: [Job] -> Value
 jobsToValue = Object . jobsToMap
@@ -18,8 +19,8 @@
 groupedJobsToValue groupedJobs =
   let mapWithoutGroups = jobsToMap $ map gjJob groupedJobs
       groupsAsMap = groupedJobsToMap groupedJobs
-      mkGroupValue group jobs acc = object [ "name" .= group, "jobs" .= jobs ] : acc
-      groupsAsValue = toJSON $ HM.foldrWithKey mkGroupValue [] groupsAsMap
+      mkGroupValue (group, jobs) acc = object [ "name" .= group, "jobs" .= jobs ] : acc
+      groupsAsValue = toJSON $ foldr mkGroupValue [] (OM.assocs groupsAsMap)
       groupsMap = HM.singleton "groups" groupsAsValue
   in Object $ HM.union mapWithoutGroups groupsMap
 
@@ -32,11 +33,12 @@
                  , ("jobs", toJSON jobs)
                  ]
 
-groupedJobsToMap :: [GroupedJob] -> HM.HashMap Text [Text]
+groupedJobsToMap :: [GroupedJob] -> OM.OMap Text [Text]
 groupedJobsToMap gjs =
   let toGroupJobsPair (GroupedJob j groups) = map (, [jobName j]) groups
       groupJobsPairs = concatMap toGroupJobsPair gjs
-  in HM.fromListWith (++) groupJobsPairs
+      foldFn pair = OM.unionWithL (\_ v1 v2 -> v1 ++ v2) (OM.fromList [pair])
+  in foldr foldFn OM.empty groupJobsPairs
 
 customResourceTypes :: [ResourceType] -> [ResourceType]
 customResourceTypes [] = []
diff --git a/test/Fly/YamlSpec.hs b/test/Fly/YamlSpec.hs
--- a/test/Fly/YamlSpec.hs
+++ b/test/Fly/YamlSpec.hs
@@ -8,6 +8,7 @@
 import Data.Aeson
 import Fly.Types
 import Fly.Yaml
+import qualified Data.HashMap.Strict as HM
 
 {-# ANN module "HLint: ignore Redundant do" #-}
 
@@ -84,7 +85,6 @@
                      , jobEnsure = Nothing
                      }
 
-    -- TODO: Make unordered assertions
     describe "jobsToValue (without groups)" $ do
       it "should translate jobs to Value as concourse expects it" $ do
         jobsToValue [testJob]
@@ -100,9 +100,35 @@
           `shouldBe` object [ "resources"      .= [gitResource, stepSlack, jobSlack]
                             , "resource_types" .= [slackResourceType]
                             , "jobs"           .= [testJob]
-                            , "groups"         .= toJSON [ object [ "name" .= "group2"
+                            , "groups"         .= toJSON [ object [ "name" .= "group1"
                                                                   , "jobs" .= [ jobName testJob ] ]
-                                                         , object [ "name" .= "group1"
+                                                         , object [ "name" .= "group2"
                                                                   , "jobs" .= [ jobName testJob ] ]
                                                          ]
                             ]
+      it "should retain order of groups" $ do
+        let testJob2 = (testJob{jobName = "test-job2"})
+        let testJob3 = (testJob{jobName = "test-job3"})
+        let groupedJob1 = GroupedJob testJob ["group1", "group2"]
+        let groupedJob2 = GroupedJob testJob2 ["group1", "group3"]
+        let groupedJob3 = GroupedJob testJob3 ["group1", "group3", "group4"]
+        let pipelineJSON = groupedJobsToValue [groupedJob1, groupedJob2, groupedJob3]
+        case pipelineJSON of
+          (Object o) ->
+            case HM.lookup "groups" o of
+              Just groups ->
+                groups `shouldBe` toJSON [ object [ "name" .= "group1"
+                                                  , "jobs" .= [ jobName testJob
+                                                              , jobName testJob2
+                                                              , jobName testJob3 ] ]
+                                         , object [ "name" .= "group2"
+                                                  , "jobs" .= [ jobName testJob ] ]
+                                         , object [ "name" .= "group3"
+                                                  , "jobs" .= [ jobName testJob2
+                                                              , jobName testJob3 ] ]
+                                         , object [ "name" .= "group4"
+                                                  , "jobs" .= [ jobName testJob3 ] ]
+
+                                         ]
+              Nothing -> fail "Expected groups to be present"
+          _ -> fail "Expected pipeline yaml to be object"