diff --git a/library/core/src/num/f128.rs b/library/core/src/num/f128.rs
index cbe1a6060de..a551ccfe9ed 100644
--- a/library/core/src/num/f128.rs
+++ b/library/core/src/num/f128.rs
@@ -1291,7 +1291,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # #[cfg(reliable_f128)] {
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// let x = 3.5_f128;
     /// let y = -3.5_f128;
@@ -1323,7 +1323,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # #[cfg(reliable_f128_math)] {
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// let f = 3.5_f128;
     ///
@@ -1360,7 +1360,7 @@ impl f128 {
     ///
     /// ```
     /// #![feature(f128)]
-    /// # #[cfg(reliable_f128_math)] {
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// let f = 3.5_f128;
     ///
diff --git a/library/core/src/num/f16.rs b/library/core/src/num/f16.rs
index 19263062c75..0d77377af74 100644
--- a/library/core/src/num/f16.rs
+++ b/library/core/src/num/f16.rs
@@ -1266,7 +1266,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(reliable_f16)] {
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// let x = 3.5_f16;
     /// let y = -3.5_f16;
@@ -1297,7 +1297,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(reliable_f16_math)] {
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// let f = 3.5_f16;
     ///
@@ -1334,7 +1334,7 @@ impl f16 {
     ///
     /// ```
     /// #![feature(f16)]
-    /// # #[cfg(reliable_f16_math)] {
+    /// # #[cfg(all(target_arch = "x86_64", target_os = "linux"))] {
     ///
     /// let f = 3.5_f16;
     ///