diff --git a/dataframe-core.cabal b/dataframe-core.cabal
--- a/dataframe-core.cabal
+++ b/dataframe-core.cabal
@@ -1,6 +1,6 @@
 cabal-version:      2.4
 name:               dataframe-core
-version:            1.0.0.0
+version:            1.0.1.0
 
 synopsis:           Core data structures for the dataframe library.
 description:
@@ -27,6 +27,7 @@
         -Wincomplete-uni-patterns
         -Wunused-imports
         -Wunused-local-binds
+        -Wunused-packages
 
 library
     import:             warnings
@@ -51,11 +52,9 @@
                         DataFrame.Typed.Types
                         DataFrame.Typed.Util
     build-depends:      base >= 4 && < 5,
-                        bytestring >= 0.11 && < 0.13,
                         containers >= 0.6.7 && < 0.9,
                         random >= 1 && < 2,
                         text >= 2.0 && < 3,
-                        time >= 1.12 && < 2,
                         vector ^>= 0.13
     hs-source-dirs:     src
     default-language:   Haskell2010
diff --git a/src/DataFrame/Internal/Hash.hs b/src/DataFrame/Internal/Hash.hs
--- a/src/DataFrame/Internal/Hash.hs
+++ b/src/DataFrame/Internal/Hash.hs
@@ -20,10 +20,13 @@
 import Data.Bits (xor)
 import Data.Char (ord)
 import qualified Data.Text as T
+import Data.Word (Word64)
 
 -- | FNV-1a 64-bit offset basis (used as the initial accumulator).
+-- The literal is unsigned and exceeds 'Int' range, so we round-trip through
+-- 'Word64' to get the well-defined two's-complement bit pattern.
 fnvOffset :: Int
-fnvOffset = 0xcbf29ce484222325
+fnvOffset = fromIntegral (0xcbf29ce484222325 :: Word64)
 
 -- | FNV-1a 64-bit prime.
 fnvPrime :: Int