diff --git a/libc/include/bits/lockf.h b/libc/include/bits/lockf.h
index a0ba19d..655514d 100644
--- a/libc/include/bits/lockf.h
+++ b/libc/include/bits/lockf.h
@@ -42,9 +42,9 @@
 #if defined(__USE_FILE_OFFSET64)
 int lockf(int, int, off_t) __RENAME(lockf64);
 #else
-int lockf(int, int, off_t);
+int lockf(int, int, off_t) __INTRODUCED_IN(24);
 #endif
-int lockf64(int, int, off64_t);
+int lockf64(int, int, off64_t) __INTRODUCED_IN(24);
 
 __END_DECLS
 
diff --git a/libc/include/bits/strcasecmp.h b/libc/include/bits/strcasecmp.h
index 124f5cd..7cb713e 100644
--- a/libc/include/bits/strcasecmp.h
+++ b/libc/include/bits/strcasecmp.h
@@ -36,9 +36,9 @@
 __BEGIN_DECLS
 
 int strcasecmp(const char*, const char*) __purefunc;
-int strcasecmp_l(const char*, const char*, locale_t) __purefunc;
+int strcasecmp_l(const char*, const char*, locale_t) __purefunc __INTRODUCED_IN(23);
 int strncasecmp(const char*, const char*, size_t) __purefunc;
-int strncasecmp_l(const char*, const char*, size_t, locale_t) __purefunc;
+int strncasecmp_l(const char*, const char*, size_t, locale_t) __purefunc __INTRODUCED_IN(23);
 
 __END_DECLS
 
diff --git a/libc/include/bits/wctype.h b/libc/include/bits/wctype.h
index 8f32aba..15ce099 100644
--- a/libc/include/bits/wctype.h
+++ b/libc/include/bits/wctype.h
@@ -37,7 +37,7 @@
 
 int iswalnum(wint_t);
 int iswalpha(wint_t);
-int iswblank(wint_t);
+int iswblank(wint_t) __INTRODUCED_IN(21);
 int iswcntrl(wint_t);
 int iswdigit(wint_t);
 int iswgraph(wint_t);
@@ -56,8 +56,8 @@
 int iswctype(wint_t, wctype_t);
 
 typedef const void* wctrans_t;
-wint_t towctrans(wint_t, wctrans_t);
-wctrans_t wctrans(const char*);
+wint_t towctrans(wint_t, wctrans_t) __INTRODUCED_IN(25);
+wctrans_t wctrans(const char*) __INTRODUCED_IN(25);
 
 __END_DECLS