diff --git a/core/src/num/f32.rs b/core/src/num/f32.rs
index 4a035ad61..d050d21c8 100644
--- a/core/src/num/f32.rs
+++ b/core/src/num/f32.rs
@@ -403,6 +403,7 @@ impl f32 {
     /// and the stability of its representation over Rust versions
     /// and target platforms isn't guaranteed.
     #[stable(feature = "assoc_int_consts", since = "1.43.0")]
+    #[rustc_diagnostic_item = "f32_nan"]
     pub const NAN: f32 = 0.0_f32 / 0.0_f32;
     /// Infinity (∞).
     #[stable(feature = "assoc_int_consts", since = "1.43.0")]
diff --git a/core/src/num/f64.rs b/core/src/num/f64.rs
index 3aafc435f..d9a738191 100644
--- a/core/src/num/f64.rs
+++ b/core/src/num/f64.rs
@@ -401,6 +401,7 @@ impl f64 {
     /// This constant isn't guaranteed to equal to any specific NaN bitpattern,
     /// and the stability of its representation over Rust versions
     /// and target platforms isn't guaranteed.
+    #[rustc_diagnostic_item = "f64_nan"]
     #[stable(feature = "assoc_int_consts", since = "1.43.0")]
     pub const NAN: f64 = 0.0_f64 / 0.0_f64;
     /// Infinity (∞).