diff --git a/libc-test/semver/solarish.txt b/libc-test/semver/solarish.txt
index 057fafb92f1de..3e672ebfb3f11 100644
--- a/libc-test/semver/solarish.txt
+++ b/libc-test/semver/solarish.txt
@@ -17,6 +17,7 @@ LIO_WRITE
 PIPE_BUF
 SIGEV_PORT
 _POSIX_VDISABLE
+_ST_FSTYPSZ
 aio_cancel
 aio_error
 aio_fsync
diff --git a/src/unix/solarish/mod.rs b/src/unix/solarish/mod.rs
index 77d0add2042bc..76acbd4fa1eb2 100644
--- a/src/unix/solarish/mod.rs
+++ b/src/unix/solarish/mod.rs
@@ -344,7 +344,7 @@ s! {
         pub st_ctime_nsec: c_long,
         pub st_blksize: crate::blksize_t,
         pub st_blocks: crate::blkcnt_t,
-        __unused: [c_char; 16],
+        pub st_fstype: [c_char; _ST_FSTYPSZ as usize],
     }
 
     pub struct termios {
@@ -2029,6 +2029,8 @@ pub const _SC_XOPEN_STREAMS: c_int = 761;
 pub const _SC_IPV6: c_int = 762;
 pub const _SC_RAW_SOCKETS: c_int = 763;
 
+pub const _ST_FSTYPSZ: c_int = 16;
+
 pub const _MUTEX_MAGIC: u16 = 0x4d58; // MX
 pub const _COND_MAGIC: u16 = 0x4356; // CV
 pub const _RWL_MAGIC: u16 = 0x5257; // RW