diff --git a/compiler/stable_mir/src/mir/alloc.rs b/compiler/stable_mir/src/mir/alloc.rs
index c780042ff261c..535808aa0ad39 100644
--- a/compiler/stable_mir/src/mir/alloc.rs
+++ b/compiler/stable_mir/src/mir/alloc.rs
@@ -55,7 +55,7 @@ impl IndexedVal for AllocId {
 /// Utility function used to read an allocation data into a unassigned integer.
 pub(crate) fn read_target_uint(mut bytes: &[u8]) -> Result<u128, Error> {
     let mut buf = [0u8; std::mem::size_of::<u128>()];
-    match MachineInfo::target_endianess() {
+    match MachineInfo::target_endianness() {
         Endian::Little => {
             bytes.read(&mut buf)?;
             Ok(u128::from_le_bytes(buf))
@@ -70,7 +70,7 @@ pub(crate) fn read_target_uint(mut bytes: &[u8]) -> Result<u128, Error> {
 /// Utility function used to read an allocation data into an assigned integer.
 pub(crate) fn read_target_int(mut bytes: &[u8]) -> Result<i128, Error> {
     let mut buf = [0u8; std::mem::size_of::<i128>()];
-    match MachineInfo::target_endianess() {
+    match MachineInfo::target_endianness() {
         Endian::Little => {
             bytes.read(&mut buf)?;
             Ok(i128::from_le_bytes(buf))
diff --git a/compiler/stable_mir/src/target.rs b/compiler/stable_mir/src/target.rs
index 3a9011a2ffe15..e00a418c54039 100644
--- a/compiler/stable_mir/src/target.rs
+++ b/compiler/stable_mir/src/target.rs
@@ -14,7 +14,7 @@ impl MachineInfo {
         with(|cx| cx.target_info())
     }
 
-    pub fn target_endianess() -> Endian {
+    pub fn target_endianness() -> Endian {
         with(|cx| cx.target_info().endian)
     }
 
diff --git a/library/core/src/intrinsics/simd.rs b/library/core/src/intrinsics/simd.rs
index 2eaca3b6fe4d5..1586481b3c97e 100644
--- a/library/core/src/intrinsics/simd.rs
+++ b/library/core/src/intrinsics/simd.rs
@@ -474,7 +474,7 @@ extern $abi {
     /// No matter whether the output is an array or an unsigned integer, it is treated as a single
     /// contiguous list of bits. The bitmask is always packed on the least-significant side of the
     /// output, and padded with 0s in the most-significant bits. The order of the bits depends on
-    /// endianess:
+    /// endianness:
     ///
     /// * On little endian, the least significant bit corresponds to the first vector element.
     /// * On big endian, the least significant bit corresponds to the last vector element.
diff --git a/src/tools/miri/src/shims/intrinsics/simd.rs b/src/tools/miri/src/shims/intrinsics/simd.rs
index c97a052f51715..aa05414ab7989 100644
--- a/src/tools/miri/src/shims/intrinsics/simd.rs
+++ b/src/tools/miri/src/shims/intrinsics/simd.rs
@@ -427,7 +427,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                 let bitmask_len = u32::try_from(bitmask_len).unwrap();
 
                 // To read the mask, we transmute it to an integer.
-                // That does the right thing wrt endianess.
+                // That does the right thing wrt endianness.
                 let mask_ty = this.machine.layouts.uint(mask.layout.size).unwrap();
                 let mask = mask.transmute(mask_ty, this)?;
                 let mask: u64 = this.read_scalar(&mask)?.to_bits(mask_ty.size)?.try_into().unwrap();
@@ -479,7 +479,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriInterpCxExt<'mir, 'tcx> {
                     }
                 }
                 // We have to change the type of the place to be able to write `res` into it. This
-                // transmutes the integer to an array, which does the right thing wrt endianess.
+                // transmutes the integer to an array, which does the right thing wrt endianness.
                 let dest =
                     dest.transmute(this.machine.layouts.uint(dest.layout.size).unwrap(), this)?;
                 this.write_int(res, &dest)?;
diff --git a/src/tools/miri/src/shims/unix/linux/fd/event.rs b/src/tools/miri/src/shims/unix/linux/fd/event.rs
index 1f17ffb88c886..49408fda3ae31 100644
--- a/src/tools/miri/src/shims/unix/linux/fd/event.rs
+++ b/src/tools/miri/src/shims/unix/linux/fd/event.rs
@@ -38,7 +38,7 @@ impl FileDescriptor for Event {
     }
 
     /// A write call adds the 8-byte integer value supplied in
-    /// its buffer (in native endianess) to the counter.  The maximum value that may be
+    /// its buffer (in native endianness) to the counter.  The maximum value that may be
     /// stored in the counter is the largest unsigned 64-bit value
     /// minus 1 (i.e., 0xfffffffffffffffe).  If the addition would
     /// cause the counter's value to exceed the maximum, then the
@@ -57,7 +57,7 @@ impl FileDescriptor for Event {
     ) -> InterpResult<'tcx, io::Result<usize>> {
         let v1 = self.val.get();
         let bytes: [u8; 8] = bytes.try_into().unwrap(); // FIXME fail gracefully when this has the wrong size
-        // Convert from target endianess to host endianess.
+        // Convert from target endianness to host endianness.
         let num = match tcx.sess.target.endian {
             Endian::Little => u64::from_le_bytes(bytes),
             Endian::Big => u64::from_be_bytes(bytes),