diff --git a/include/stdlib.h b/include/stdlib.h
index f1beaaa4138d..b8dddedb6f30 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -227,7 +227,7 @@ __uint32_t
 	 arc4random(void);
 void	 arc4random_addrandom(unsigned char *dat, int datlen);
 void	 arc4random_stir(void);
-char	*getbsize(size_t *, long *);
+char	*getbsize(int *, long *);
 					/* getcap(3) functions */
 char	*cgetcap(char *, const char *, int);
 int	 cgetclose(void);
diff --git a/lib/libc/gen/getbsize.3 b/lib/libc/gen/getbsize.3
index f91f8ba35cc4..cbf48630f94b 100644
--- a/lib/libc/gen/getbsize.3
+++ b/lib/libc/gen/getbsize.3
@@ -43,7 +43,7 @@
 .Sh SYNOPSIS
 .In stdlib.h
 .Ft char *
-.Fn getbsize "size_t *headerlenp" "long *blocksizep"
+.Fn getbsize "int *headerlenp" "long *blocksizep"
 .Sh DESCRIPTION
 The
 .Fn getbsize
diff --git a/lib/libc/gen/getbsize.c b/lib/libc/gen/getbsize.c
index 11e5ef751b6a..1a3a70d07ebb 100644
--- a/lib/libc/gen/getbsize.c
+++ b/lib/libc/gen/getbsize.c
@@ -44,7 +44,7 @@ __FBSDID("$FreeBSD$");
 
 char *
 getbsize(headerlenp, blocksizep)
-	size_t *headerlenp;
+	int *headerlenp;
 	long *blocksizep;
 {
 	static char header[20];