diff --git a/libs/libc/libc.csv b/libs/libc/libc.csv
index a436c1d8a5b..c164c910f90 100644
--- a/libs/libc/libc.csv
+++ b/libs/libc/libc.csv
@@ -75,6 +75,21 @@
 "inet_ntoa","arpa/inet.h","defined(CONFIG_NET_IPv4)","FAR char *","struct in_addr"
 "inet_ntop","arpa/inet.h","","FAR const char","int","FAR const void *","FAR char *","socklen_t"
 "inet_pton","arpa/inet.h","","int","int","FAR const char *","FAR void *"
+"isspace","ctype.h","","int","int"
+"isascii","ctype.h","","int","int"
+"isprint","ctype.h","","int","int"
+"isgraph","ctype.h","","int","int"
+"iscntrl","ctype.h","","int","int"
+"islower","ctype.h","","int","int"
+"isupper","ctype.h","","int","int"
+"isalpha","ctype.h","","int","int"
+"isblank","ctype.h","","int","int"
+"isdigit","ctype.h","","int","int"
+"isalnum","ctype.h","","int","int"
+"ispunct","ctype.h","","int","int"
+"isxdigit","ctype.h","","int","int"
+"toupper","ctype.h","","int","int"
+"tolower","ctype.h","","int","int"
 "iswalnum","wctype.h","defined(CONFIG_LIBC_WCHAR)","int","wint_t"
 "iswalpha","wctype.h","defined(CONFIG_LIBC_WCHAR)","int","wint_t"
 "iswblank","wctype.h","defined(CONFIG_LIBC_WCHAR)","int","wint_t"