diff --git a/Gonito/ExtractMetadata.hs b/Gonito/ExtractMetadata.hs
index e542000..516d37d 100644
--- a/Gonito/ExtractMetadata.hs
+++ b/Gonito/ExtractMetadata.hs
@@ -30,7 +30,7 @@ import "Glob" System.FilePath.Glob as G
 
 data ExtractionOptions = ExtractionOptions {
   extractionOptionsDescription :: Maybe Text,
-  extractionOptionsTags :: Maybe Text,
+  extractionOptionsTags :: Maybe (S.Set Text),
   extractionOptionsGeneralParams :: Maybe (M.Map Text Text),
   extractionOptionsUnwantedParams :: Maybe [Text],
   extractionOptionsParamFiles :: Maybe [String],
@@ -74,7 +74,7 @@ combineExtractionOptions :: Maybe ExtractionOptions -> ExtractionOptions -> Extr
 combineExtractionOptions Nothing options = options
 combineExtractionOptions (Just otherOptions) options = ExtractionOptions {
   extractionOptionsDescription = combineWithT extractionOptionsDescription,
-  extractionOptionsTags = combineWithT extractionOptionsTags,
+  extractionOptionsTags = combineWithS extractionOptionsTags,
   extractionOptionsGeneralParams = Just $ (fromMaybe M.empty $ extractionOptionsGeneralParams options)
                                           `M.union`
                                           (fromMaybe M.empty $ extractionOptionsGeneralParams otherOptions),
@@ -86,11 +86,16 @@ combineExtractionOptions (Just otherOptions) options = ExtractionOptions {
                                   Just pfs -> Just pfs,
   extractionOptionsMLRunPath = combineWithF extractionOptionsMLRunPath }
   where combineWithT fun = case fun options of
-                            Nothing -> fun otherOptions
-                            Just v -> Just v
+                             Nothing -> fun otherOptions
+                             Just v -> Just v
         combineWithF fun = case fun options of
-                            Nothing -> fun otherOptions
-                            Just v -> Just v
+                             Nothing -> fun otherOptions
+                             Just v -> Just v
+        combineWithS fun = case fun options of
+                             Nothing -> fun otherOptions
+                             Just s1 -> case fun otherOptions of
+                               Nothing -> Just s1
+                               Just s2 -> Just (s1 `S.union` s2)
 
 extractMetadataFromRepoDir :: FilePath -> ExtractionOptions -> IO GonitoMetadata
 extractMetadataFromRepoDir repoDir formExtractionOptions = do
@@ -108,8 +113,8 @@ extractMetadataFromRepoDir repoDir formExtractionOptions = do
                         Nothing -> "???"
 
   let commitTagsParsed = parseTags mCommitTags
-  let formTagsParsed = parseTags $ extractionOptionsTags extractionOptions
-  let tagsParsed = union commitTagsParsed formTagsParsed
+  let formTagsParsed = extractionOptionsTags extractionOptions
+  let tagsParsed = union commitTagsParsed $ fromMaybe S.empty formTagsParsed
 
   paramFiles <- case extractionOptionsParamFiles extractionOptions of
     Just paramFilesGlobs -> G.globDir (Import.map G.compile paramFilesGlobs) repoDir
diff --git a/Handler/ShowChallenge.hs b/Handler/ShowChallenge.hs
index e2c0312..e041333 100644
--- a/Handler/ShowChallenge.hs
+++ b/Handler/ShowChallenge.hs
@@ -20,7 +20,10 @@ import Handler.Tables
 import Handler.TagUtils
 import Handler.MakePublic
 
-import Gonito.ExtractMetadata (ExtractionOptions(..), extractMetadataFromRepoDir, GonitoMetadata(..))
+import Gonito.ExtractMetadata (ExtractionOptions(..),
+                               extractMetadataFromRepoDir,
+                               GonitoMetadata(..),
+                               parseTags)
 
 import qualified Text.Read as TR
 
@@ -242,7 +245,7 @@ doCreateSubmission userId challengeId mDescription mTags repoSpec chan = do
       gonitoMetadata <- liftIO
                        $ extractMetadataFromRepoDir repoDir (ExtractionOptions {
                                                                 extractionOptionsDescription = mDescription,
-                                                                extractionOptionsTags = mTags,
+                                                                extractionOptionsTags = Just $ parseTags mTags,
                                                                 extractionOptionsGeneralParams = Nothing,
                                                                 extractionOptionsUnwantedParams = Nothing,
                                                                 extractionOptionsParamFiles = Nothing,
diff --git a/test/Gonito/ExtractMetadataSpec.hs b/test/Gonito/ExtractMetadataSpec.hs
index 51f2c48..5d8ea2a 100644
--- a/test/Gonito/ExtractMetadataSpec.hs
+++ b/test/Gonito/ExtractMetadataSpec.hs
@@ -22,7 +22,7 @@ spec = do
     it "simple with some fields from the form" $ do
       extractMetadataFromRepoDir "test/fake-git-repos/simple/" def {
         extractionOptionsDescription = Just "Other solution",
-        extractionOptionsTags = Just "other-tag,baz"
+        extractionOptionsTags = Just $ S.fromList ["other-tag", "baz"]
         } `shouldReturn` GonitoMetadata {
         gonitoMetadataDescription = "Other solution",
         gonitoMetadataTags = S.fromList ["foo", "simple-solution", "baz", "other-tag"],
diff --git a/test/fake-git-repos/with-gonito-yaml b/test/fake-git-repos/with-gonito-yaml
index a71de45..262f063 160000
--- a/test/fake-git-repos/with-gonito-yaml
+++ b/test/fake-git-repos/with-gonito-yaml
@@ -1 +1 @@
-Subproject commit a71de45eacb63081b2b39db09c48ad3d848c2541
+Subproject commit 262f063bfbdb6417fbc4589ea6dfb60be773e6b1