diff --git a/winsup/cygwin/include/cygwin/stdlib.h b/winsup/cygwin/include/cygwin/stdlib.h
index 00615a9ef..01c56463e 100644
--- a/winsup/cygwin/include/cygwin/stdlib.h
+++ b/winsup/cygwin/include/cygwin/stdlib.h
@@ -19,12 +19,6 @@ extern "C"
 {
 #endif
 
-__uint32_t arc4random(void);
-void arc4random_addrandom(unsigned char *, int);
-void arc4random_buf(void *, size_t);
-void arc4random_stir(void);
-__uint32_t arc4random_uniform(__uint32_t);
-
 const char *getprogname (void);
 void	setprogname (const char *);