diff --git a/clang/lib/Tooling/Inclusions/Stdlib/StdSpecialSymbolMap.inc b/clang/lib/Tooling/Inclusions/Stdlib/StdSpecialSymbolMap.inc
index 165c1fc2eebc2..0d351d688a329 100644
--- a/clang/lib/Tooling/Inclusions/Stdlib/StdSpecialSymbolMap.inc
+++ b/clang/lib/Tooling/Inclusions/Stdlib/StdSpecialSymbolMap.inc
@@ -367,6 +367,16 @@ SYMBOL(any_cast, std::, <any>)
 SYMBOL(div, std::, <cstdlib>)
 SYMBOL(abort, std::, <cstdlib>)
 
+// These are C symbols that are not under std namespace.
+SYMBOL(localtime_r, None, <ctime>)
+SYMBOL(localtime_r, None, <time.h>)
+SYMBOL(localtime_s, None, <ctime>)
+SYMBOL(localtime_s, None, <time.h>)
+SYMBOL(gmtime_r, None, <ctime>)
+SYMBOL(gmtime_r, None, <time.h>)
+SYMBOL(gmtime_s, None, <ctime>)
+SYMBOL(gmtime_s, None, <time.h>)
+
 // The std::placeholder symbols (_1, ..., _N) are listed in the cppreference
 // placeholder.html, but the index only contains a single entry with "_1, _2, ..., _N"
 // text, which are not handled by the script.