diff --git a/reactos/lib/crtdll/stdlib/obsol.c b/reactos/lib/crtdll/stdlib/obsol.c
index 59f8fc45b7d..6f686bb85bf 100644
--- a/reactos/lib/crtdll/stdlib/obsol.c
+++ b/reactos/lib/crtdll/stdlib/obsol.c
@@ -5,10 +5,6 @@
 unsigned char _cpumode = 0;
 unsigned char *_cpumode_dll = &_cpumode;
 
-WINBOOL STDCALL Beep(DWORD dwFreq, DWORD dwDuration);
-VOID    STDCALL Sleep(DWORD dwMilliseconds);
-UINT    STDCALL SetErrorMode(UINT uMode);
-
 /*
  * @implemented
  */
diff --git a/reactos/lib/msvcrt/stdlib/obsol.c b/reactos/lib/msvcrt/stdlib/obsol.c
index 59f8fc45b7d..6f686bb85bf 100644
--- a/reactos/lib/msvcrt/stdlib/obsol.c
+++ b/reactos/lib/msvcrt/stdlib/obsol.c
@@ -5,10 +5,6 @@
 unsigned char _cpumode = 0;
 unsigned char *_cpumode_dll = &_cpumode;
 
-WINBOOL STDCALL Beep(DWORD dwFreq, DWORD dwDuration);
-VOID    STDCALL Sleep(DWORD dwMilliseconds);
-UINT    STDCALL SetErrorMode(UINT uMode);
-
 /*
  * @implemented
  */