diff --git a/src/Arguments.hs b/src/Arguments.hs
index 3934fde7a..b2df4613d 100644
--- a/src/Arguments.hs
+++ b/src/Arguments.hs
@@ -30,6 +30,7 @@ data CmdLineOptions = CmdLineOptions
   { outputFormat :: R.Format
   , maybeTimeout :: Maybe Float
   , outputFilePath :: Maybe FilePath
+  , blobEntry :: Maybe String
   , noIndex :: Bool
   , extraArgs :: [ExtraArg]
   , developmentMode' :: Bool
diff --git a/src/SemanticDiff.hs b/src/SemanticDiff.hs
index 21e6b7255..34cbca548 100644
--- a/src/SemanticDiff.hs
+++ b/src/SemanticDiff.hs
@@ -41,6 +41,7 @@ argumentsParser = info (version <*> helper <*> argumentsP)
       <|> flag' R.ParseTree (long "parse-tree" <> help "output JSON parse tree structure"))
       <*> optional (option auto (long "timeout" <> help "timeout for per-file diffs in seconds, defaults to 7 seconds"))
       <*> optional (strOption (long "output" <> short 'o' <> help "output directory for split diffs, defaults to stdout if unspecified"))
+      <*> optional (strOption (long "blob" <> short 'b' <> help "blob entry for parsing"))
       <*> switch (long "no-index" <> help "compare two paths on the filesystem")
       <*> some (argument (eitherReader parseShasAndFiles) (metavar "SHA_A..SHAB FILES..."))
       <*> switch (long "development" <> short 'd' <> help "set development mode which prevents timeout behavior by default")