diff --git a/simple-tar.cabal b/simple-tar.cabal
--- a/simple-tar.cabal
+++ b/simple-tar.cabal
@@ -1,5 +1,5 @@
 name:          simple-tar
-version:       0.5
+version:       0.5.1
 license:       BSD3
 license-file:  LICENSE
 author:        Adam Wick <awick@galois.com>
diff --git a/src/Codec/Archive/Tar.hs b/src/Codec/Archive/Tar.hs
--- a/src/Codec/Archive/Tar.hs
+++ b/src/Codec/Archive/Tar.hs
@@ -15,6 +15,7 @@
 import qualified Data.ByteString as B
 import qualified Data.ByteString.Char8 as BC
 import           Data.Char(digitToInt)
+import           Data.List(isPrefixOf)
 import           Data.Map.Strict(Map)
 import qualified Data.Map.Strict as Map
 import           Data.Serialize.Get
@@ -281,7 +282,8 @@
      hdrDeviceMinor      <- toNumeric       `fmap` getByteString 8
      hdrPrefix           <- toStringLike    `fmap` getByteString 155
      skip 12 -- trailing bytes
-     unless (hdrMagic == "ustar ") $ fail ("Bad magic value: " ++ hdrMagic ++ "(filename: " ++ show hdrFileName)
+     unless ("ustar" `isPrefixOf` hdrMagic) $
+       fail ("Bad magic value: " ++ hdrMagic ++ " (fname: " ++ show hdrFileName)
      return ArchiveHeader{..}
 
 data RecordTypeFlag = FlagRegularFile
@@ -328,6 +330,7 @@
   parseOctal acc x =
     case BC.uncons x of
       Nothing        -> acc
+      Just (' ',  _) -> acc
       Just ('\0', _) -> acc
       Just (c, rest) -> parseOctal ((acc * 8) + digitToInt' c) rest
   digitToInt' = fromIntegral . digitToInt