diff --git a/is/error.go b/is/error.go
index 9249a66..d3d92d6 100644
--- a/is/error.go
+++ b/is/error.go
@@ -32,6 +32,8 @@ func Error(got, target error) expect.Expectation {
 // NoError expects v to be nil.
 func NoError(v error) expect.Expectation {
 	return expect.ExpectFunc(func(t expect.TB) {
+		t.Helper()
+
 		if v != nil {
 			t.Errorf("expected no error but got %q", v)
 		}
diff --git a/is/map.go b/is/map.go
index 4499d77..0569f52 100644
--- a/is/map.go
+++ b/is/map.go
@@ -22,6 +22,8 @@ func MapContaining[T ~map[K]V, K, V comparable](got T, key K, val V) expect.Expe
 // MapOfLen expects got to contain want elements.
 func MapOfLen[T ~map[K]V, K comparable, V any](got T, want int) expect.Expectation {
 	return expect.ExpectFunc(func(t expect.TB) {
+		t.Helper()
+
 		gotLen := len(got)
 		if gotLen != want {
 			t.Errorf("expected %v to have len %d but got %d", got, want, gotLen)
diff --git a/is/string.go b/is/string.go
index 619376f..8626293 100644
--- a/is/string.go
+++ b/is/string.go
@@ -9,6 +9,8 @@ import (
 // StringOfLen expects got to have byte length want.
 func StringOfLen(got string, want int) expect.Expectation {
 	return expect.ExpectFunc(func(t expect.TB) {
+		t.Helper()
+
 		gotLen := len(got)
 		if gotLen != want {
 			t.Errorf("expected %q to have len %d but got %d", got, want, gotLen)