diff --git a/libc/unistd/pwrite.c b/libc/unistd/pwrite.c
index ea080d2..223e1b3 100644
--- a/libc/unistd/pwrite.c
+++ b/libc/unistd/pwrite.c
@@ -28,9 +28,9 @@
 #include <sys/types.h>
 #include <unistd.h>
 
-extern int __pwrite64(int fd, void *buf, size_t nbytes, loff_t offset);
+extern int __pwrite64(int fd, const void *buf, size_t nbytes, loff_t offset);
 
-ssize_t pwrite(int fd, void *buf, size_t nbytes, off_t offset)
+ssize_t pwrite(int fd, const void *buf, size_t nbytes, off_t offset)
 {
     return __pwrite64(fd, buf, nbytes, offset);
 }