diff --git a/library/core/src/num/f128.rs b/library/core/src/num/f128.rs
index 8fb1588e60b35..5e45974b3d422 100644
--- a/library/core/src/num/f128.rs
+++ b/library/core/src/num/f128.rs
@@ -670,7 +670,8 @@ impl f128 {
     /// If one of the arguments is NaN, then the other argument is returned.
     /// This follows the IEEE 754-2008 semantics for maxNum, except for handling of signaling NaNs;
     /// this function handles all NaNs the same way and avoids maxNum's problems with associativity.
-    /// This also matches the behavior of libm’s fmax.
+    /// This also matches the behavior of libm’s fmax. In particular, if the inputs compare equal
+    /// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
     ///
     /// ```
     /// #![feature(f128)]
@@ -696,7 +697,8 @@ impl f128 {
     /// If one of the arguments is NaN, then the other argument is returned.
     /// This follows the IEEE 754-2008 semantics for minNum, except for handling of signaling NaNs;
     /// this function handles all NaNs the same way and avoids minNum's problems with associativity.
-    /// This also matches the behavior of libm’s fmin.
+    /// This also matches the behavior of libm’s fmin. In particular, if the inputs compare equal
+    /// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
     ///
     /// ```
     /// #![feature(f128)]
diff --git a/library/core/src/num/f16.rs b/library/core/src/num/f16.rs
index 8c2af74b8f842..e3176cd168852 100644
--- a/library/core/src/num/f16.rs
+++ b/library/core/src/num/f16.rs
@@ -662,7 +662,8 @@ impl f16 {
     /// If one of the arguments is NaN, then the other argument is returned.
     /// This follows the IEEE 754-2008 semantics for maxNum, except for handling of signaling NaNs;
     /// this function handles all NaNs the same way and avoids maxNum's problems with associativity.
-    /// This also matches the behavior of libm’s fmax.
+    /// This also matches the behavior of libm’s fmax. In particular, if the inputs compare equal
+    /// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
     ///
     /// ```
     /// #![feature(f16)]
@@ -687,7 +688,8 @@ impl f16 {
     /// If one of the arguments is NaN, then the other argument is returned.
     /// This follows the IEEE 754-2008 semantics for minNum, except for handling of signaling NaNs;
     /// this function handles all NaNs the same way and avoids minNum's problems with associativity.
-    /// This also matches the behavior of libm’s fmin.
+    /// This also matches the behavior of libm’s fmin. In particular, if the inputs compare equal
+    /// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
     ///
     /// ```
     /// #![feature(f16)]
diff --git a/library/core/src/num/f32.rs b/library/core/src/num/f32.rs
index 817bedbd44f98..4d42997369ffb 100644
--- a/library/core/src/num/f32.rs
+++ b/library/core/src/num/f32.rs
@@ -874,7 +874,8 @@ impl f32 {
     /// If one of the arguments is NaN, then the other argument is returned.
     /// This follows the IEEE 754-2008 semantics for maxNum, except for handling of signaling NaNs;
     /// this function handles all NaNs the same way and avoids maxNum's problems with associativity.
-    /// This also matches the behavior of libm’s fmax.
+    /// This also matches the behavior of libm’s fmax. In particular, if the inputs compare equal
+    /// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
     ///
     /// ```
     /// let x = 1.0f32;
@@ -895,7 +896,8 @@ impl f32 {
     /// If one of the arguments is NaN, then the other argument is returned.
     /// This follows the IEEE 754-2008 semantics for minNum, except for handling of signaling NaNs;
     /// this function handles all NaNs the same way and avoids minNum's problems with associativity.
-    /// This also matches the behavior of libm’s fmin.
+    /// This also matches the behavior of libm’s fmin. In particular, if the inputs compare equal
+    /// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
     ///
     /// ```
     /// let x = 1.0f32;
diff --git a/library/core/src/num/f64.rs b/library/core/src/num/f64.rs
index 1b0651a0def07..907971d303ffc 100644
--- a/library/core/src/num/f64.rs
+++ b/library/core/src/num/f64.rs
@@ -892,7 +892,8 @@ impl f64 {
     /// If one of the arguments is NaN, then the other argument is returned.
     /// This follows the IEEE 754-2008 semantics for maxNum, except for handling of signaling NaNs;
     /// this function handles all NaNs the same way and avoids maxNum's problems with associativity.
-    /// This also matches the behavior of libm’s fmax.
+    /// This also matches the behavior of libm’s fmax. In particular, if the inputs compare equal
+    /// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
     ///
     /// ```
     /// let x = 1.0_f64;
@@ -913,7 +914,8 @@ impl f64 {
     /// If one of the arguments is NaN, then the other argument is returned.
     /// This follows the IEEE 754-2008 semantics for minNum, except for handling of signaling NaNs;
     /// this function handles all NaNs the same way and avoids minNum's problems with associativity.
-    /// This also matches the behavior of libm’s fmin.
+    /// This also matches the behavior of libm’s fmin. In particular, if the inputs compare equal
+    /// (such as for the case of `+0.0` and `-0.0`), either input may be returned non-deterministically.
     ///
     /// ```
     /// let x = 1.0_f64;