diff --git a/CHANGELOG b/CHANGELOG
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,5 +1,9 @@
 # Changelog
 
+- 0.1.6 (2026-08-01)
+  * The eq_{word,wide,wider}# functions now return a mask, instead of a
+    bit, inside the resulting Choice value.
+
 - 0.1.5 (2026-06-07)
   * Improves constant-time modular inverse performance on the Montgomery
     'Curve' module by about 2x, and on the 'Scalar' module by about 1.5x.
diff --git a/lib/Data/Choice.hs b/lib/Data/Choice.hs
--- a/lib/Data/Choice.hs
+++ b/lib/Data/Choice.hs
@@ -347,7 +347,7 @@
   let !s = case B.finiteBitSize (0 :: Word) of I# m -> m Exts.-# 1#
       !x = Exts.xor# a b
       !y = Exts.uncheckedShiftRL# (Exts.or# x (neg_w# x)) s
-  in  Choice (Exts.xor# y 1##)
+  in  from_bit# (Exts.xor# y 1##)
 {-# INLINE eq_word# #-}
 
 -- | Compare unboxed two-limb words for equality in constant time.
@@ -362,7 +362,7 @@
   let !s = case B.finiteBitSize (0 :: Word) of I# m -> m Exts.-# 1#
       !x = Exts.or# (Exts.xor# a0 b0) (Exts.xor# a1 b1)
       !y = Exts.uncheckedShiftRL# (Exts.or# x (neg_w# x)) s
-  in  Choice (Exts.xor# y 1##)
+  in  from_bit# (Exts.xor# y 1##)
 {-# INLINE eq_wide# #-}
 
 -- | Compare unboxed four-limb words for equality in constant time.
@@ -378,6 +378,6 @@
       !x = Exts.or# (Exts.or# (Exts.xor# a0 b0) (Exts.xor# a1 b1))
                     (Exts.or# (Exts.xor# a2 b2) (Exts.xor# a3 b3))
       !y = Exts.uncheckedShiftRL# (Exts.or# x (neg_w# x)) s
-  in  Choice (Exts.xor# y 1##)
+  in  from_bit# (Exts.xor# y 1##)
 {-# INLINE eq_wider# #-}
 
diff --git a/ppad-fixed.cabal b/ppad-fixed.cabal
--- a/ppad-fixed.cabal
+++ b/ppad-fixed.cabal
@@ -1,6 +1,6 @@
 cabal-version:      3.0
 name:               ppad-fixed
-version:            0.1.5
+version:            0.1.6
 synopsis:           Large fixed-width words and constant-time arithmetic.
 license:            MIT
 license-file:       LICENSE
diff --git a/test/Limb.hs b/test/Limb.hs
--- a/test/Limb.hs
+++ b/test/Limb.hs
@@ -84,6 +84,11 @@
   H.assertBool mempty (not (C.decide (L.eq# a b)))
   H.assertBool mempty (not (C.decide (L.eq# b a)))
   H.assertBool mempty (C.decide (L.eq# b b))
+  -- eq# must yield a full-word mask, not a bare bit; negating or
+  -- selecting on it is otherwise wrong
+  H.assertBool mempty (not (C.decide (L.ne# a a)))
+  H.assertBool mempty (C.decide (L.ne# a b))
+  H.assertBool mempty (L.eq_vartime# (L.select# a b (L.eq# a a)) b)
 
 gt :: H.Assertion
 gt = do
diff --git a/test/Wide.hs b/test/Wide.hs
--- a/test/Wide.hs
+++ b/test/Wide.hs
@@ -6,6 +6,7 @@
     tests
   ) where
 
+import qualified Data.Choice as C
 import qualified Data.Word.Wide as W
 import Test.Tasty
 import qualified Test.Tasty.HUnit as H
@@ -32,11 +33,25 @@
   let !r = W.add (2 ^ (128 :: Word) - 1) 1
   H.assertBool mempty (W.eq_vartime r 0)
 
+eq :: H.Assertion
+eq = do
+  let !a = 0 :: W.Wide
+      !b = 2 ^ (128 :: Word) - 1
+  H.assertBool mempty (C.decide (W.eq a a))
+  H.assertBool mempty (not (C.decide (W.eq a b)))
+  H.assertBool mempty (C.decide (W.eq b b))
+  -- eq must yield a full-word mask, not a bare bit; negating or
+  -- selecting on it is otherwise wrong
+  H.assertBool mempty (not (C.decide (C.not (W.eq a a))))
+  H.assertBool mempty (C.decide (C.not (W.eq a b)))
+  H.assertBool mempty (W.eq_vartime (W.select a b (W.eq a a)) b)
+
 tests :: TestTree
 tests = testGroup "wide tests" [
     H.testCase "overflowing add, no carry" overflowing_add_no_carry
   , H.testCase "overflowing add, carry" overflowing_add_with_carry
   , H.testCase "wrapping add, no carry" wrapping_add_no_carry
   , H.testCase "wrapping add, carry" wrapping_add_with_carry
+  , H.testCase "eq" eq
   ]
 
diff --git a/test/Wider.hs b/test/Wider.hs
--- a/test/Wider.hs
+++ b/test/Wider.hs
@@ -67,6 +67,12 @@
   H.assertBool mempty (not (C.decide (W.eq# a b)))
   H.assertBool mempty (not (C.decide (W.eq# b a)))
   H.assertBool mempty (C.decide (W.eq# b b))
+  -- eq# must yield a full-word mask, not a bare bit; negating or
+  -- selecting on it is otherwise wrong
+  H.assertBool mempty (not (C.decide (C.not (W.eq# a a))))
+  H.assertBool mempty (C.decide (C.not (W.eq# a b)))
+  H.assertBool mempty
+    (W.eq_vartime (W.select (W.Wider a) (W.Wider b) (W.eq# a a)) (W.Wider b))
 
 gt :: H.Assertion
 gt = do