diff --git a/std/math/emulated/field_assert.go b/std/math/emulated/field_assert.go
index ce6d5dbf9c..692db8ef2e 100644
--- a/std/math/emulated/field_assert.go
+++ b/std/math/emulated/field_assert.go
@@ -128,7 +128,7 @@ func (f *Field[T]) AssertIsEqual(a, b *Element[T]) {
 		return
 	}
 
-	diff := f.subNoReduce(b, a)
+	diff := f.Sub(b, a)
 
 	// we compute k such that diff / p == k
 	// so essentially, we say "I know an element k such that k*p == diff"
diff --git a/std/math/emulated/regression_test.go b/std/math/emulated/regression_test.go
index daff5822b0..440cbc00aa 100644
--- a/std/math/emulated/regression_test.go
+++ b/std/math/emulated/regression_test.go
@@ -94,3 +94,27 @@ func TestIssue867Division(t *testing.T) {
 	}
 	test.IsSolved(&testIssue867Circuit{A: ac, B: bc}, &testIssue867Circuit{A: a, B: b}, ecc.BLS12_381.ScalarField())
 }
+
+type testIssue1021Circuit struct {
+	A Element[BN254Fp]
+}
+
+func (c *testIssue1021Circuit) Define(api frontend.API) error {
+	f, err := NewField[BN254Fp](api)
+	if err != nil {
+		return err
+	}
+	b := f.NewElement(c.A)
+	p := f.Modulus()
+	for i := 0; i < 188; i++ {
+		b = f.Add(b, p)
+	}
+	f.AssertIsEqual(b, &c.A)
+	return nil
+}
+
+func TestIssue1021(t *testing.T) {
+	assert := test.NewAssert(t)
+	err := test.IsSolved(&testIssue1021Circuit{}, &testIssue1021Circuit{A: ValueOf[BN254Fp](10)}, ecc.BN254.ScalarField())
+	assert.NoError(err)
+}