diff --git a/encode.go b/encode.go
index 1d4aa05..bf876dd 100644
--- a/encode.go
+++ b/encode.go
@@ -831,7 +831,8 @@ func (e *encoder) writeFloat(v float64) error {
 	case math.IsInf(v, -1):
 		e.buf.WriteString("-inf")
 	case v == 0:
-		// Normalise negative zero to positive zero (TOML has no -0).
+		// Normalise negative zero to positive zero, the contract the output
+		// rules in the documentation state.
 		e.buf.WriteString("0.0")
 	default:
 		s := strconv.FormatFloat(v, 'g', -1, 64)
diff --git a/encode_test.go b/encode_test.go
index cb5c8f8..8f03d52 100644
--- a/encode_test.go
+++ b/encode_test.go
@@ -67,7 +67,7 @@ func TestMarshalFloatSpecials(t *testing.T) {
 }
 
 func TestMarshalFloatNormalizesNegativeZero(t *testing.T) {
-	// TOML has no -0; the emitter must normalise negative zero to "0.0".
+	// The output contract normalises negative zero to "0.0".
 	type Cfg struct {
 		Z float64 `toml:"z"`
 	}