diff --git a/src/libcore/num/f32.rs b/src/libcore/num/f32.rs
index 9e379e638103e..be1e566fafdfa 100644
--- a/src/libcore/num/f32.rs
+++ b/src/libcore/num/f32.rs
@@ -62,7 +62,7 @@ pub const NAN: f32 = 0.0_f32 / 0.0_f32;
 /// Infinity (∞).
 #[stable(feature = "rust1", since = "1.0.0")]
 pub const INFINITY: f32 = 1.0_f32 / 0.0_f32;
-/// Negative infinity (-∞).
+/// Negative infinity (−∞).
 #[stable(feature = "rust1", since = "1.0.0")]
 pub const NEG_INFINITY: f32 = -1.0_f32 / 0.0_f32;
 
diff --git a/src/libcore/num/f64.rs b/src/libcore/num/f64.rs
index 540c6a529d7c8..feadb43ff98dd 100644
--- a/src/libcore/num/f64.rs
+++ b/src/libcore/num/f64.rs
@@ -62,7 +62,7 @@ pub const NAN: f64 = 0.0_f64 / 0.0_f64;
 /// Infinity (∞).
 #[stable(feature = "rust1", since = "1.0.0")]
 pub const INFINITY: f64 = 1.0_f64 / 0.0_f64;
-/// Negative infinity (-∞).
+/// Negative infinity (−∞).
 #[stable(feature = "rust1", since = "1.0.0")]
 pub const NEG_INFINITY: f64 = -1.0_f64 / 0.0_f64;