diff --git a/src/hash.rs b/src/hash.rs
index de535d4..038316c 100644
--- a/src/hash.rs
+++ b/src/hash.rs
@@ -1,7 +1,9 @@
 /// A fast seedable 32-bit hash function.
 pub fn hash_u32(mut n: u32, seed: u32) -> u32 {
-    n ^= 0xe6fe3beb; // So zero doesn't map to zero.
-    n ^= seed;
+    // We rotate the bits of `seed` so it's unlikely to interact with `n`
+    // in bad ways if they're both e.g. incrementing.  The particular
+    // rotation constant used here isn't special.
+    n ^= seed.rotate_left(23);
 
     // From https://github.com/skeeto/hash-prospector
     n ^= n >> 16;
@@ -10,15 +12,17 @@ pub fn hash_u32(mut n: u32, seed: u32) -> u32 {
     n = n.wrapping_mul(0xd35a2d97);
     n ^= n >> 15;
 
-    // We xor by `seed` again in case the first time cancelled out our
-    // "zero doesn't map to zero" precaution.
-    n ^ seed
+    // Xor by a random number so input zero doesn't map to output zero.
+    // The particular number used here isn't special.
+    n ^ 0xe6fe3beb
 }
 
 /// A fast seedable 64-bit hash function.
 pub fn hash_u64(mut n: u64, seed: u64) -> u64 {
-    n ^= 0x4acc3f27cc712c9d; // So zero doesn't map to zero.
-    n ^= seed;
+    // We rotate the bits of `seed` so it's unlikely to interact with `n`
+    // in bad ways if they're both e.g. incrementing.  The particular
+    // rotation constant used here isn't special.
+    n ^= seed.rotate_left(47);
 
     // From https://zimbry.blogspot.com/2011/09/better-bit-mixing-improving-on.html
     n ^= n >> 30;
@@ -27,9 +31,9 @@ pub fn hash_u64(mut n: u64, seed: u64) -> u64 {
     n = n.wrapping_mul(0x94d049bb133111eb);
     n ^= n >> 31;
 
-    // We xor by `seed` again in case the first time cancelled out our
-    // "zero doesn't map to zero" precaution.
-    n ^ seed
+    // Xor by a random number so input zero doesn't map to output zero.
+    // The particular number used here isn't special.
+    n ^ 0x4acc3f27cc712c9d
 }
 
 /// Returns a random float in [0, 1] based on 'n' and a seed.