diff --git a/libc/include/bits/fcntl.h b/libc/include/bits/fcntl.h
index 604d35a..e3b0e8c 100644
--- a/libc/include/bits/fcntl.h
+++ b/libc/include/bits/fcntl.h
@@ -33,7 +33,7 @@
 
 __BEGIN_DECLS
 
-int fcntl(int, int, ...);
+int fcntl(int __fd, int __cmd, ...);
 
 __END_DECLS
 
diff --git a/libc/include/bits/getopt.h b/libc/include/bits/getopt.h
index 7153d48..5481449 100644
--- a/libc/include/bits/getopt.h
+++ b/libc/include/bits/getopt.h
@@ -33,9 +33,9 @@
 
 __BEGIN_DECLS
 
-int	 getopt(int, char * const [], const char *);
+int getopt(int __argc, char* const __argv[], const char* __options);
 
-extern char *optarg;			/* getopt(3) external variables */
+extern char* optarg;
 extern int optind, opterr, optopt;
 
 __END_DECLS
diff --git a/libc/include/bits/ioctl.h b/libc/include/bits/ioctl.h
index 53116ca..0cf87d2 100644
--- a/libc/include/bits/ioctl.h
+++ b/libc/include/bits/ioctl.h
@@ -33,7 +33,7 @@
 
 __BEGIN_DECLS
 
-int ioctl(int, int, ...);
+int ioctl(int __fd, int __request, ...);
 
 __END_DECLS
 
diff --git a/libc/include/bits/lockf.h b/libc/include/bits/lockf.h
index a8e273e..929c68c 100644
--- a/libc/include/bits/lockf.h
+++ b/libc/include/bits/lockf.h
@@ -39,8 +39,8 @@
 
 __BEGIN_DECLS
 
-int lockf(int, int, off_t) __RENAME_IF_FILE_OFFSET64(lockf64) __INTRODUCED_IN(24);
-int lockf64(int, int, off64_t) __INTRODUCED_IN(24);
+int lockf(int __fd, int __cmd, off_t __length) __RENAME_IF_FILE_OFFSET64(lockf64) __INTRODUCED_IN(24);
+int lockf64(int __fd, int __cmd, off64_t __length) __INTRODUCED_IN(24);
 
 __END_DECLS
 
diff --git a/libc/include/bits/strcasecmp.h b/libc/include/bits/strcasecmp.h
index df1a6b8..594046a 100644
--- a/libc/include/bits/strcasecmp.h
+++ b/libc/include/bits/strcasecmp.h
@@ -35,10 +35,10 @@
 
 __BEGIN_DECLS
 
-int strcasecmp(const char*, const char*) __attribute_pure__;
-int strcasecmp_l(const char*, const char*, locale_t) __attribute_pure__ __INTRODUCED_IN(23);
-int strncasecmp(const char*, const char*, size_t) __attribute_pure__;
-int strncasecmp_l(const char*, const char*, size_t, locale_t) __attribute_pure__ __INTRODUCED_IN(23);
+int strcasecmp(const char* __s1, const char* __s2) __attribute_pure__;
+int strcasecmp_l(const char* __s1, const char* __s2, locale_t __l) __attribute_pure__ __INTRODUCED_IN(23);
+int strncasecmp(const char* __s1, const char* __s2, size_t __n) __attribute_pure__;
+int strncasecmp_l(const char* __s1, const char* __s2, size_t __n, locale_t __l) __attribute_pure__ __INTRODUCED_IN(23);
 
 __END_DECLS
 
diff --git a/libc/include/bits/wctype.h b/libc/include/bits/wctype.h
index f21d46e..a51eca2 100644
--- a/libc/include/bits/wctype.h
+++ b/libc/include/bits/wctype.h
@@ -37,29 +37,29 @@
 
 #define WEOF __BIONIC_CAST(static_cast, wint_t, -1)
 
-int iswalnum(wint_t);
-int iswalpha(wint_t);
-int iswblank(wint_t) __INTRODUCED_IN(21);
-int iswcntrl(wint_t);
-int iswdigit(wint_t);
-int iswgraph(wint_t);
-int iswlower(wint_t);
-int iswprint(wint_t);
-int iswpunct(wint_t);
-int iswspace(wint_t);
-int iswupper(wint_t);
-int iswxdigit(wint_t);
+int iswalnum(wint_t __wc);
+int iswalpha(wint_t __wc);
+int iswblank(wint_t __wc) __INTRODUCED_IN(21);
+int iswcntrl(wint_t __wc);
+int iswdigit(wint_t __wc);
+int iswgraph(wint_t __wc);
+int iswlower(wint_t __wc);
+int iswprint(wint_t __wc);
+int iswpunct(wint_t __wc);
+int iswspace(wint_t __wc);
+int iswupper(wint_t __wc);
+int iswxdigit(wint_t __wc);
 
-wint_t towlower(wint_t);
-wint_t towupper(wint_t);
+wint_t towlower(wint_t __wc);
+wint_t towupper(wint_t __wc);
 
 typedef long wctype_t;
-wctype_t wctype(const char*);
-int iswctype(wint_t, wctype_t);
+wctype_t wctype(const char* __name);
+int iswctype(wint_t __wc, wctype_t __type);
 
 typedef const void* wctrans_t;
-wint_t towctrans(wint_t, wctrans_t) __INTRODUCED_IN(26) __VERSIONER_NO_GUARD;
-wctrans_t wctrans(const char*) __INTRODUCED_IN(26) __VERSIONER_NO_GUARD;
+wint_t towctrans(wint_t __wc, wctrans_t __transform) __INTRODUCED_IN(26) __VERSIONER_NO_GUARD;
+wctrans_t wctrans(const char* __name) __INTRODUCED_IN(26) __VERSIONER_NO_GUARD;
 
 __END_DECLS