diff --git a/crypto/ec/curve448/curve448utils.h b/crypto/ec/curve448/curve448utils.h
index 91fea6abf5fa9fb4a3ab70569c51bdfc665cc34a..22438895948e39944b2eaf48c044c893b9f0d86f 100644
--- a/crypto/ec/curve448/curve448utils.h
+++ b/crypto/ec/curve448/curve448utils.h
@@ -15,10 +15,6 @@
 
 # include <openssl/e_os2.h>
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 /*
  * Internal word types. Somewhat tricky.  This could be decided separately per
  * platform.  However, the structs do need to be all the same size and
@@ -79,8 +75,4 @@ static ossl_inline c448_error_t c448_succeed_if(c448_bool_t x)
     return (c448_error_t) x;
 }
 
-#ifdef __cplusplus
-} /* extern "C" */
-#endif
-
 #endif                          /* __C448_COMMON_H__ */
diff --git a/crypto/ec/curve448/ed448.h b/crypto/ec/curve448/ed448.h
index 303443d09ea392ee3c97bef9cd7f82f0f9e5a037..eec66296fe5e47c819135f5b514bf64b55d6b660 100644
--- a/crypto/ec/curve448/ed448.h
+++ b/crypto/ec/curve448/ed448.h
@@ -15,10 +15,6 @@
 
 # include "point_448.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 /* Number of bytes in an EdDSA public key. */
 # define EDDSA_448_PUBLIC_BYTES 57
 
@@ -200,8 +196,4 @@ c448_error_t c448_ed448_convert_private_key_to_x448(
                             uint8_t x[X448_PRIVATE_BYTES],
                             const uint8_t ed[EDDSA_448_PRIVATE_BYTES]);
 
-#ifdef __cplusplus
-} /* extern "C" */
-#endif
-
 #endif                          /* __C448_ED448_H__ */
diff --git a/crypto/ec/curve448/point_448.h b/crypto/ec/curve448/point_448.h
index 8b7aacde9775f585b915380d8aaed21bd84bef97..90a7c3ba05716f51eab6ed517e9410a71b551070 100644
--- a/crypto/ec/curve448/point_448.h
+++ b/crypto/ec/curve448/point_448.h
@@ -16,9 +16,6 @@
 # include "curve448utils.h"
 # include "field.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
 
 # define C448_SCALAR_LIMBS ((446-1)/C448_WORD_BITS+1)
 
@@ -283,8 +280,4 @@ void curve448_scalar_destroy(curve448_scalar_t scalar);
 /* Overwrite point with zeros. */
 void curve448_point_destroy(curve448_point_t point);
 
-#ifdef __cplusplus
-} /* extern "C" */
-#endif
-
 #endif                          /* __C448_POINT_448_H__ */