diff --git a/libc/arch-sh/syscalls.mk b/libc/arch-sh/syscalls.mk
index 493f437..9575905 100644
--- a/libc/arch-sh/syscalls.mk
+++ b/libc/arch-sh/syscalls.mk
@@ -45,8 +45,8 @@
 syscall_src += arch-sh/syscalls/acct.S
 syscall_src += arch-sh/syscalls/read.S
 syscall_src += arch-sh/syscalls/write.S
-syscall_src += arch-sh/syscalls/__pread64.S
-syscall_src += arch-sh/syscalls/__pwrite64.S
+syscall_src += arch-sh/syscalls/pread64.S
+syscall_src += arch-sh/syscalls/pwrite64.S
 syscall_src += arch-sh/syscalls/__open.S
 syscall_src += arch-sh/syscalls/__openat.S
 syscall_src += arch-sh/syscalls/close.S
@@ -73,6 +73,7 @@
 syscall_src += arch-sh/syscalls/dup2.S
 syscall_src += arch-sh/syscalls/select.S
 syscall_src += arch-sh/syscalls/ftruncate.S
+syscall_src += arch-sh/syscalls/ftruncate64.S
 syscall_src += arch-sh/syscalls/getdents.S
 syscall_src += arch-sh/syscalls/fsync.S
 syscall_src += arch-sh/syscalls/fdatasync.S
diff --git a/libc/arch-sh/syscalls/__pwrite64.S b/libc/arch-sh/syscalls/ftruncate64.S
similarity index 63%
copy from libc/arch-sh/syscalls/__pwrite64.S
copy to libc/arch-sh/syscalls/ftruncate64.S
index a722242..f4c7c1e 100644
--- a/libc/arch-sh/syscalls/__pwrite64.S
+++ b/libc/arch-sh/syscalls/ftruncate64.S
@@ -2,22 +2,19 @@
 #include <sys/linux-syscalls.h>
 
     .text
-    .type __pwrite64, @function
-    .globl __pwrite64
+    .type ftruncate64, @function
+    .globl ftruncate64
     .align 4
 
-__pwrite64:
-
-    /* get ready for additonal arg */
-    mov.l   @r15, r0
+ftruncate64:
 
     /* invoke trap */
     mov.l   0f, r3  /* trap num */
-    trapa   #(5 + 0x10)
+    trapa   #(3 + 0x10)
 
     /* check return value */
     cmp/pz  r0
-    bt      __NR_pwrite64_end
+    bt      __NR_ftruncate64_end
 
     /* keep error number */
     sts.l   pr, @-r15
@@ -26,10 +23,10 @@
     mov     r0, r4
     lds.l   @r15+, pr
 
-__NR_pwrite64_end:
+__NR_ftruncate64_end:
     rts
     nop
 
     .align  2
-0:  .long   __NR_pwrite64
+0:  .long   __NR_ftruncate64
 1:  .long   __set_syscall_errno
diff --git a/libc/arch-sh/syscalls/__pread64.S b/libc/arch-sh/syscalls/pread64.S
similarity index 89%
rename from libc/arch-sh/syscalls/__pread64.S
rename to libc/arch-sh/syscalls/pread64.S
index 474add3..702a402 100644
--- a/libc/arch-sh/syscalls/__pread64.S
+++ b/libc/arch-sh/syscalls/pread64.S
@@ -2,11 +2,11 @@
 #include <sys/linux-syscalls.h>
 
     .text
-    .type __pread64, @function
-    .globl __pread64
+    .type pread64, @function
+    .globl pread64
     .align 4
 
-__pread64:
+pread64:
 
     /* get ready for additonal arg */
     mov.l   @r15, r0
diff --git a/libc/arch-sh/syscalls/__pwrite64.S b/libc/arch-sh/syscalls/pwrite64.S
similarity index 89%
rename from libc/arch-sh/syscalls/__pwrite64.S
rename to libc/arch-sh/syscalls/pwrite64.S
index a722242..3f6c192 100644
--- a/libc/arch-sh/syscalls/__pwrite64.S
+++ b/libc/arch-sh/syscalls/pwrite64.S
@@ -2,11 +2,11 @@
 #include <sys/linux-syscalls.h>
 
     .text
-    .type __pwrite64, @function
-    .globl __pwrite64
+    .type pwrite64, @function
+    .globl pwrite64
     .align 4
 
-__pwrite64:
+pwrite64:
 
     /* get ready for additonal arg */
     mov.l   @r15, r0