diff --git a/libc/SYSCALLS.TXT b/libc/SYSCALLS.TXT
index d698133a3..46e7b1f72 100644
--- a/libc/SYSCALLS.TXT
+++ b/libc/SYSCALLS.TXT
@@ -76,6 +76,8 @@ int     setpgid(pid_t, pid_t)  57
 pid_t   vfork(void)  190,-1,190
 int     setregid:setregid32(gid_t, gid_t)  204
 int     chroot(const char *)  61
+# IMPORTANT: Even though <sys/prctl.h> declares prctl(int,...), the syscall stub must take 6 arguments
+#            to match the kernel implementation.
 int     prctl(int option, unsigned int arg2, unsigned int arg3, unsigned int arg4, unsigned int arg5)  172
 int     capget(cap_user_header_t header, cap_user_data_t data) 184
 int     capset(cap_user_header_t header, const cap_user_data_t data) 185
diff --git a/libc/include/sys/prctl.h b/libc/include/sys/prctl.h
index ce85bf7e0..359d684f3 100644
--- a/libc/include/sys/prctl.h
+++ b/libc/include/sys/prctl.h
@@ -32,8 +32,13 @@
 
 __BEGIN_DECLS
 
-extern int prctl(int option, unsigned long arg2, unsigned long arg3 , unsigned
-               long arg4, unsigned long arg5);
+/* IMPORTANT NOTE: This function is declared as taking a variable number
+ *                 of arguments to match the GLibc definition. However
+ *                 its declaration inside SYSCALLS.TXT *must* make it
+ *                 take 6 arguments to ensure consistency with the kernel
+ *                 implementation.
+ */
+extern int prctl(int option, ...);
 
 __END_DECLS
 
diff --git a/libc/include/unistd.h b/libc/include/unistd.h
index 4534fb9c1..d92549fb3 100644
--- a/libc/include/unistd.h
+++ b/libc/include/unistd.h
@@ -70,8 +70,9 @@ extern int execlp(const char *, const char *, ...);
 extern int execle(const char *, const char *, ...);
 extern int capget(cap_user_header_t hdrp, cap_user_data_t datap);
 extern int capset(cap_user_header_t hdrp, const cap_user_data_t datap);
-extern int prctl(int  option,  unsigned long arg2, unsigned long arg3,
-                 unsigned long arg4, unsigned long arg5);
+
+/* IMPORTANT: See comment under <sys/prctl.h> about this declaration */
+extern int prctl(int  option, ...);
 
 extern int nice(int);