diff --git a/src/field/goldilocks_field.rs b/src/field/goldilocks_field.rs
index 7378ea15..a7d46363 100644
--- a/src/field/goldilocks_field.rs
+++ b/src/field/goldilocks_field.rs
@@ -13,6 +13,7 @@ use crate::field::extension_field::quartic::QuarticExtension;
 use crate::field::extension_field::Extendable;
 use crate::field::field_types::{Field, PrimeField, RichField};
 use crate::field::inversion::try_inverse_u64;
+use crate::util::assume;
 
 const EPSILON: u64 = (1 << 32) - 1;
 
@@ -280,6 +281,8 @@ unsafe fn add_with_wraparound(x: u64, y: u64) -> u64 {
         inlateout(reg) y => adjustment,
         options(pure, nomem, nostack),
     );
+    assume(x != 0 || (res_wrapped == y && adjustment == 0));
+    assume(y != 0 || (res_wrapped == x && adjustment == 0));
     res_wrapped.wrapping_add(adjustment) // Add EPSILON == subtract ORDER.
 }
 
@@ -307,6 +310,7 @@ unsafe fn sub_with_wraparound(x: u64, y: u64) -> u64 {
         inlateout(reg) y => adjustment,
         options(pure, nomem, nostack),
     );
+    assume(y != 0 || (res_wrapped == x && adjustment == 0));
     res_wrapped.wrapping_sub(adjustment) // Subtract EPSILON == add ORDER.
 }
 
diff --git a/src/util/mod.rs b/src/util/mod.rs
index d8e05a18..94df5141 100644
--- a/src/util/mod.rs
+++ b/src/util/mod.rs
@@ -1,3 +1,5 @@
+use core::hint::unreachable_unchecked;
+
 use crate::field::field_types::Field;
 use crate::polynomial::polynomial::PolynomialValues;
 
@@ -195,6 +197,14 @@ pub(crate) fn reverse_bits(n: usize, num_bits: usize) -> usize {
         .0
 }
 
+#[inline(always)]
+pub(crate) unsafe fn assume(p: bool) {
+    debug_assert!(p);
+    if !p {
+        unreachable_unchecked();
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use crate::util::{reverse_bits, reverse_index_bits, reverse_index_bits_in_place};