diff --git a/scientific-notation.cabal b/scientific-notation.cabal
--- a/scientific-notation.cabal
+++ b/scientific-notation.cabal
@@ -1,6 +1,6 @@
 cabal-version: 2.2
 name: scientific-notation
-version: 0.1.0.0
+version: 0.1.0.1
 synopsis: Scientific notation intended for tokenization
 description:
   This library provides a type used to represent a number in
@@ -49,7 +49,7 @@
   exposed-modules: Data.Number.Scientific
   build-depends:
     , base >=4.12 && <5
-    , bytesmith >=0.2.0.1 && <0.3
+    , bytesmith >=0.3 && <0.4
   hs-source-dirs: src
   default-language: Haskell2010
 
diff --git a/src/Data/Number/Scientific.hs b/src/Data/Number/Scientific.hs
--- a/src/Data/Number/Scientific.hs
+++ b/src/Data/Number/Scientific.hs
@@ -39,7 +39,7 @@
 import GHC.Exts (Int#,Word#,Int(I#),(+#))
 import GHC.Word (Word(W#),Word8(W8#),Word16(W16#),Word32(W32#),Word64(W64#))
 import GHC.Int (Int64(I64#),Int32(I32#))
-import Data.Bytes.Parser (Parser(..))
+import Data.Bytes.Parser.Unsafe (Parser(..))
 import Data.Fixed (Fixed(MkFixed),HasResolution)
 
 import qualified Data.Fixed as Fixed
diff --git a/test/Main.hs b/test/Main.hs
--- a/test/Main.hs
+++ b/test/Main.hs
@@ -131,29 +131,29 @@
   , testGroup "Parser"
     [ testGroup "UTF-8-signed"
       [ testProperty "small-integer" $ \i ->
-          P.Success (small i 0) 0
+          let str = show i in
+          P.Success (P.Slice (length str + 1) 0 (small i 0))
           ===
-          P.parseBytes (SCI.parserSignedUtf8Bytes ())
-            (bytes (show i))
+          P.parseBytes (SCI.parserSignedUtf8Bytes ()) (bytes str)
       , testProperty "small-exp" $ \i j b ->
-          P.Success (small i j) 0
+          let str = show i ++ bool "e" "E" b ++ show j in
+          P.Success (P.Slice (length str + 1) 0 (small i j))
           ===
-          P.parseBytes (SCI.parserSignedUtf8Bytes ())
-            (bytes (show i ++ bool "e" "E" b ++ show j))
+          P.parseBytes (SCI.parserSignedUtf8Bytes ()) (bytes str)
       , testProperty "fixed-e12-no-exp" $ \(i :: Fixed E12) ->
-          QC.counterexample (show i)
+          let str = show i in
+          QC.counterexample str
           $
-          P.Success (SCI.fromFixed i) 0
+          P.Success (P.Slice (length str + 1) 0 (SCI.fromFixed i))
           ===
-          P.parseBytes (SCI.parserSignedUtf8Bytes ())
-            (bytes (show i))
+          P.parseBytes (SCI.parserSignedUtf8Bytes ()) (bytes str)
       , testProperty "large-integer" $ \(LargeInteger i) (LargeInteger j) ->
-          QC.counterexample (show (large i j))
+          let str = show (large i j) in
+          QC.counterexample str
           $
-          P.Success (large i j) 0
+          P.Success (P.Slice (length str + 1) 0 (large i j))
           ===
-          P.parseBytes (SCI.parserSignedUtf8Bytes ())
-            (bytes (show (large i j)))
+          P.parseBytes (SCI.parserSignedUtf8Bytes ()) (bytes str)
       ]
     ]
   ]