diff --git a/library/core/src/lib.rs b/library/core/src/lib.rs
index 19cd05de2a7..7294adaccd3 100644
--- a/library/core/src/lib.rs
+++ b/library/core/src/lib.rs
@@ -73,6 +73,7 @@
 #![feature(const_discriminant)]
 #![feature(const_checked_int_methods)]
 #![feature(const_euclidean_int_methods)]
+#![feature(const_float_bits_conv)]
 #![feature(const_overflowing_int_methods)]
 #![feature(const_int_unchecked_arith)]
 #![feature(const_int_pow)]
diff --git a/library/core/src/num/f32.rs b/library/core/src/num/f32.rs
index 9fb7296ce31..2d2d99ef6ee 100644
--- a/library/core/src/num/f32.rs
+++ b/library/core/src/num/f32.rs
@@ -652,8 +652,9 @@ impl f32 {
     ///
     /// ```
     #[stable(feature = "float_bits_conv", since = "1.20.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn to_bits(self) -> u32 {
+    pub const fn to_bits(self) -> u32 {
         // SAFETY: `u32` is a plain old datatype so we can always transmute to it
         unsafe { mem::transmute(self) }
     }
@@ -695,8 +696,9 @@ impl f32 {
     /// assert_eq!(v, 12.5);
     /// ```
     #[stable(feature = "float_bits_conv", since = "1.20.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn from_bits(v: u32) -> Self {
+    pub const fn from_bits(v: u32) -> Self {
         // SAFETY: `u32` is a plain old datatype so we can always transmute from it
         // It turns out the safety issues with sNaN were overblown! Hooray!
         unsafe { mem::transmute(v) }
@@ -712,8 +714,9 @@ impl f32 {
     /// assert_eq!(bytes, [0x41, 0x48, 0x00, 0x00]);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn to_be_bytes(self) -> [u8; 4] {
+    pub const fn to_be_bytes(self) -> [u8; 4] {
         self.to_bits().to_be_bytes()
     }
 
@@ -727,8 +730,9 @@ impl f32 {
     /// assert_eq!(bytes, [0x00, 0x00, 0x48, 0x41]);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn to_le_bytes(self) -> [u8; 4] {
+    pub const fn to_le_bytes(self) -> [u8; 4] {
         self.to_bits().to_le_bytes()
     }
 
@@ -755,8 +759,9 @@ impl f32 {
     /// );
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn to_ne_bytes(self) -> [u8; 4] {
+    pub const fn to_ne_bytes(self) -> [u8; 4] {
         self.to_bits().to_ne_bytes()
     }
 
@@ -769,8 +774,9 @@ impl f32 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn from_be_bytes(bytes: [u8; 4]) -> Self {
+    pub const fn from_be_bytes(bytes: [u8; 4]) -> Self {
         Self::from_bits(u32::from_be_bytes(bytes))
     }
 
@@ -783,8 +789,9 @@ impl f32 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn from_le_bytes(bytes: [u8; 4]) -> Self {
+    pub const fn from_le_bytes(bytes: [u8; 4]) -> Self {
         Self::from_bits(u32::from_le_bytes(bytes))
     }
 
@@ -808,8 +815,9 @@ impl f32 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn from_ne_bytes(bytes: [u8; 4]) -> Self {
+    pub const fn from_ne_bytes(bytes: [u8; 4]) -> Self {
         Self::from_bits(u32::from_ne_bytes(bytes))
     }
 
diff --git a/library/core/src/num/f64.rs b/library/core/src/num/f64.rs
index a5b1eb3f1fd..82ea82fe2be 100644
--- a/library/core/src/num/f64.rs
+++ b/library/core/src/num/f64.rs
@@ -666,8 +666,9 @@ impl f64 {
     ///
     /// ```
     #[stable(feature = "float_bits_conv", since = "1.20.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn to_bits(self) -> u64 {
+    pub const fn to_bits(self) -> u64 {
         // SAFETY: `u64` is a plain old datatype so we can always transmute to it
         unsafe { mem::transmute(self) }
     }
@@ -709,8 +710,9 @@ impl f64 {
     /// assert_eq!(v, 12.5);
     /// ```
     #[stable(feature = "float_bits_conv", since = "1.20.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn from_bits(v: u64) -> Self {
+    pub const fn from_bits(v: u64) -> Self {
         // SAFETY: `u64` is a plain old datatype so we can always transmute from it
         // It turns out the safety issues with sNaN were overblown! Hooray!
         unsafe { mem::transmute(v) }
@@ -726,8 +728,9 @@ impl f64 {
     /// assert_eq!(bytes, [0x40, 0x29, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00]);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn to_be_bytes(self) -> [u8; 8] {
+    pub const fn to_be_bytes(self) -> [u8; 8] {
         self.to_bits().to_be_bytes()
     }
 
@@ -741,8 +744,9 @@ impl f64 {
     /// assert_eq!(bytes, [0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x29, 0x40]);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn to_le_bytes(self) -> [u8; 8] {
+    pub const fn to_le_bytes(self) -> [u8; 8] {
         self.to_bits().to_le_bytes()
     }
 
@@ -769,8 +773,9 @@ impl f64 {
     /// );
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn to_ne_bytes(self) -> [u8; 8] {
+    pub const fn to_ne_bytes(self) -> [u8; 8] {
         self.to_bits().to_ne_bytes()
     }
 
@@ -783,8 +788,9 @@ impl f64 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn from_be_bytes(bytes: [u8; 8]) -> Self {
+    pub const fn from_be_bytes(bytes: [u8; 8]) -> Self {
         Self::from_bits(u64::from_be_bytes(bytes))
     }
 
@@ -797,8 +803,9 @@ impl f64 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn from_le_bytes(bytes: [u8; 8]) -> Self {
+    pub const fn from_le_bytes(bytes: [u8; 8]) -> Self {
         Self::from_bits(u64::from_le_bytes(bytes))
     }
 
@@ -822,8 +829,9 @@ impl f64 {
     /// assert_eq!(value, 12.5);
     /// ```
     #[stable(feature = "float_to_from_bytes", since = "1.40.0")]
+    #[rustc_const_unstable(feature = "const_float_bits_conv", issue = "72447")]
     #[inline]
-    pub fn from_ne_bytes(bytes: [u8; 8]) -> Self {
+    pub const fn from_ne_bytes(bytes: [u8; 8]) -> Self {
         Self::from_bits(u64::from_ne_bytes(bytes))
     }