diff --git a/CryptoPkg/Library/BaseCryptLib/SysCall/ConstantTimeClock.c b/CryptoPkg/Library/BaseCryptLib/SysCall/ConstantTimeClock.c
index b625246bda..224e3c3642 100644
--- a/CryptoPkg/Library/BaseCryptLib/SysCall/ConstantTimeClock.c
+++ b/CryptoPkg/Library/BaseCryptLib/SysCall/ConstantTimeClock.c
@@ -43,6 +43,14 @@ gmtime (
   return NULL;
 }
 
+time_t
+mktime (
+  struct tm  *t
+  )
+{
+  return 0;
+}
+
 unsigned int
 sleep (
   unsigned int  seconds
diff --git a/CryptoPkg/Library/BaseCryptLib/SysCall/TimerWrapper.c b/CryptoPkg/Library/BaseCryptLib/SysCall/TimerWrapper.c
index 2e83041cf8..21b79acccd 100644
--- a/CryptoPkg/Library/BaseCryptLib/SysCall/TimerWrapper.c
+++ b/CryptoPkg/Library/BaseCryptLib/SysCall/TimerWrapper.c
@@ -141,6 +141,24 @@ time (
   return CalTime;
 }
 
+time_t
+mktime (
+  struct tm  *t
+  )
+{
+  EFI_TIME  Time = {
+    .Year     = (UINT16)t->tm_year,
+    .Month    = (UINT8)t->tm_mon,
+    .Day      = (UINT8)t->tm_mday,
+    .Hour     = (UINT8)t->tm_hour,
+    .Minute   = (UINT8)t->tm_min,
+    .Second   = (UINT8)t->tm_sec,
+    .TimeZone = EFI_UNSPECIFIED_TIMEZONE,
+  };
+
+  return CalculateTimeT (&Time);
+}
+
 //
 // Convert a time value from type time_t to struct tm.
 //
diff --git a/CryptoPkg/Library/Include/CrtLibSupport.h b/CryptoPkg/Library/Include/CrtLibSupport.h
index f81f490734..e3e8781d16 100644
--- a/CryptoPkg/Library/Include/CrtLibSupport.h
+++ b/CryptoPkg/Library/Include/CrtLibSupport.h
@@ -348,6 +348,11 @@ gettimeofday (
   struct timezone  *tz
   );
 
+time_t
+mktime (
+  struct tm  *t
+  );
+
 uid_t
 getuid      (
   void