diff --git a/sourcemap.cabal b/sourcemap.cabal
--- a/sourcemap.cabal
+++ b/sourcemap.cabal
@@ -1,5 +1,5 @@
 name:                sourcemap
-version:             0.1.2.0
+version:             0.1.3.0
 synopsis:            Implementation of source maps as proposed by Google and Mozilla.
 description:         Implementation of source maps, revision 3, proposed by Google and Mozilla here
                      <https://wiki.mozilla.org/DevTools/Features/SourceMap> and here
diff --git a/src/SourceMap.hs b/src/SourceMap.hs
--- a/src/SourceMap.hs
+++ b/src/SourceMap.hs
@@ -22,6 +22,7 @@
 import           Data.Ord
 import           Data.STRef
 import           Data.Text (Text)
+import           Data.Text.Lazy.Encoding (decodeUtf8)
 
 -- | Generate the JSON from a source mapping.
 generate :: SourceMapping -> Value
@@ -30,7 +31,7 @@
         ,("file",toJSON smFile)
         ,("sources",toJSON sources)
         ,("names",toJSON names)
-        ,("mappings",toJSON (encodeMappings sources names smMappings))] ++
+        ,("mappings",toJSON (decodeUtf8 (encodeMappings sources names smMappings)))] ++
         [("sourceRoot",toJSON root) | Just root <- [smSourceRoot]]
   names = nub $ mapMaybe mapName smMappings
   sources = symbols mapSourceFile