diff --git a/Include/pyport.h b/Include/pyport.h
index baa04fee17b..944b83adff6 100644
--- a/Include/pyport.h
+++ b/Include/pyport.h
@@ -866,7 +866,7 @@ extern pid_t forkpty(int *, char *, struct termios *, struct winsize *);
 #endif
 
 /*
- * Convenient macros to deal with endianess of the platform. WORDS_BIGENDIAN is
+ * Convenient macros to deal with endianness of the platform. WORDS_BIGENDIAN is
  * detected by configure and defined in pyconfig.h. The code in pyconfig.h
  * also also takes care of Apple's universal builds.
  */
diff --git a/Misc/NEWS b/Misc/NEWS
index dde91212fca..ad2530b634f 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -20,7 +20,7 @@ Core and Builtins
   user that created them, even when the source file is read-only.
 
 - Issue #16166: Add PY_LITTLE_ENDIAN and PY_BIG_ENDIAN macros and unified
-  endianess detection and handling.
+  endianness detection and handling.
 
 - Issue #15958: bytes.join and bytearray.join now accept arbitrary buffer
   objects.