diff --git a/include/poll.h b/include/poll.h
index 7b42866..24691f1 100644
--- a/include/poll.h
+++ b/include/poll.h
@@ -16,7 +16,9 @@
 #ifndef _FORTIFY_POLL_H
 #define _FORTIFY_POLL_H
 
+#ifndef __cplusplus
 __extension__
+#endif
 #include_next <poll.h>
 
 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0
diff --git a/include/stdio.h b/include/stdio.h
index b67f9ce..a965184 100644
--- a/include/stdio.h
+++ b/include/stdio.h
@@ -16,7 +16,9 @@
 #ifndef _FORTIFY_STDIO_H
 #define _FORTIFY_STDIO_H
 
+#ifndef __cplusplus
 __extension__
+#endif
 #include_next <stdio.h>
 
 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0
diff --git a/include/stdlib.h b/include/stdlib.h
index 7ff5746..ef70995 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -16,12 +16,16 @@
 #ifndef _FORTIFY_STDLIB_H
 #define _FORTIFY_STDLIB_H
 
+#ifndef __cplusplus
 __extension__
+#endif
 #include_next <stdlib.h>
 
 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0
 #if defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
+#ifndef __cplusplus
 __extension__
+#endif
 #include_next <limits.h>
 #endif
 
diff --git a/include/string.h b/include/string.h
index ff237b0..43c7485 100644
--- a/include/string.h
+++ b/include/string.h
@@ -16,7 +16,9 @@
 #ifndef _FORTIFY_STRING_H
 #define _FORTIFY_STRING_H
 
+#ifndef __cplusplus
 __extension__
+#endif
 #include_next <string.h>
 
 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0
diff --git a/include/sys/select.h b/include/sys/select.h
index e4e398f..bcee8be 100644
--- a/include/sys/select.h
+++ b/include/sys/select.h
@@ -16,7 +16,9 @@
 #ifndef _FORTIFY_SYS_SELECT_H
 #define _FORTIFY_SYS_SELECT_H
 
+#ifndef __cplusplus
 __extension__
+#endif
 #include_next <sys/select.h>
 
 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0
diff --git a/include/sys/socket.h b/include/sys/socket.h
index 7d3f023..ad6ab2d 100644
--- a/include/sys/socket.h
+++ b/include/sys/socket.h
@@ -16,7 +16,9 @@
 #ifndef _FORTIFY_SYS_SOCKET_H
 #define _FORTIFY_SYS_SOCKET_H
 
+#ifndef __cplusplus
 __extension__
+#endif
 #include_next <sys/socket.h>
 
 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0
diff --git a/include/unistd.h b/include/unistd.h
index d3ab246..71dda84 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -16,7 +16,9 @@
 #ifndef _FORTIFY_UNISTD_H
 #define _FORTIFY_UNISTD_H
 
+#ifndef __cplusplus
 __extension__
+#endif
 #include_next <unistd.h>
 
 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0
diff --git a/include/wchar.h b/include/wchar.h
index 7394598..3cb6f92 100644
--- a/include/wchar.h
+++ b/include/wchar.h
@@ -16,13 +16,21 @@
 #ifndef _FORTIFY_WCHAR_H
 #define _FORTIFY_WCHAR_H
 
+#ifndef __cplusplus
 __extension__
+#endif
 #include_next <limits.h>
+#ifndef __cplusplus
 __extension__
+#endif
 #include_next <stdlib.h>
+#ifndef __cplusplus
 __extension__
+#endif
 #include_next <string.h>
+#ifndef __cplusplus
 __extension__
+#endif
 #include_next <wchar.h>
 
 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0