diff --git a/rules/cstdlib/tgt_refcount.rs b/rules/cstdlib/tgt_refcount.rs
index cb04f452..a965f5b0 100644
--- a/rules/cstdlib/tgt_refcount.rs
+++ b/rules/cstdlib/tgt_refcount.rs
@@ -30,6 +30,26 @@ fn f6(a0: Ptr<u8>) -> Ptr<u8> {
     }
 }
 
+fn f10(a0: Ptr<u8>, a1: Ptr<u8>) -> Ptr<u8> {
+    let __resolved = a1.clone();
+    match ::std::fs::canonicalize(a0.to_rust_string()) {
+        Ok(__p) => {
+            let mut __bytes = __p.into_os_string().into_encoded_bytes();
+            __bytes.push(0);
+            if __resolved.is_null() {
+                Ptr::alloc_array(__bytes.into_boxed_slice())
+            } else {
+                __resolved.with_slice_mut(__bytes.len(), |__s| __s.copy_from_slice(&__bytes));
+                __resolved
+            }
+        }
+        Err(__e) => {
+            libcc2rs::cpp2rust_errno().write(__e.raw_os_error().unwrap_or(::libc::EIO));
+            Ptr::null()
+        }
+    }
+}
+
 fn f8(a0: AnyPtr, a1: AnyPtr, a2: usize, a3: usize, a4: fn(AnyPtr, AnyPtr) -> i32) -> AnyPtr {
     let __base = a1.reinterpret_cast::<u8>();
     let mut __lo: isize = 0;
diff --git a/tests/unit/out/unsafe/stdlib_h.rs b/tests/unit/out/unsafe/stdlib_h.rs
index 2a9d6e03..674bcb94 100644
--- a/tests/unit/out/unsafe/stdlib_h.rs
+++ b/tests/unit/out/unsafe/stdlib_h.rs
@@ -36,6 +36,42 @@ pub unsafe fn test_setenv_getenv_0() {
         ((((libc::strcmp(v, (c"replaced".as_ptr().cast_mut()).cast_const())) == (0)) as i32) != 0)
     );
 }
+pub unsafe fn test_realpath_1() {
+    let mut buf: [libc::c_char; 4096] = [(0 as libc::c_char); 4096];
+    assert!(
+        (((!((libc::realpath((c"/".as_ptr().cast_mut()).cast_const(), buf.as_mut_ptr())).is_null()))
+            as i32)
+            != 0)
+    );
+    assert!(
+        ((((libc::strcmp(
+            (buf.as_mut_ptr()).cast_const(),
+            (c"/".as_ptr().cast_mut()).cast_const()
+        )) == (0)) as i32)
+            != 0)
+    );
+    let mut p: *mut libc::c_char = libc::realpath(
+        (c"/".as_ptr().cast_mut()).cast_const(),
+        std::ptr::null_mut(),
+    );
+    assert!((((!((p).is_null())) as i32) != 0));
+    assert!(
+        ((((libc::strcmp((p).cast_const(), (c"/".as_ptr().cast_mut()).cast_const())) == (0))
+            as i32)
+            != 0)
+    );
+    libcc2rs::free_unsafe((p as *mut libc::c_char as *mut ::libc::c_void));
+    (*libcc2rs::cpp2rust_errno_unsafe()) = 0;
+    assert!(
+        ((((libc::realpath(
+            (c"/cpp2rust_definitely_missing".as_ptr().cast_mut()).cast_const(),
+            buf.as_mut_ptr()
+        ))
+        .is_null()) as i32)
+            != 0)
+    );
+    assert!(((((*libcc2rs::cpp2rust_errno_unsafe()) == (2)) as i32) != 0));
+}
 pub fn main() {
     unsafe {
         std::process::exit(main_0() as i32);
@@ -43,5 +79,6 @@ pub fn main() {
 }
 unsafe fn main_0() -> i32 {
     (unsafe { test_setenv_getenv_0() });
+    (unsafe { test_realpath_1() });
     return 0;
 }
diff --git a/tests/unit/stdlib_h.c b/tests/unit/stdlib_h.c
index 724a9a17..91250b56 100644
--- a/tests/unit/stdlib_h.c
+++ b/tests/unit/stdlib_h.c
@@ -1,5 +1,6 @@
 // no-compile: refcount
 #include <assert.h>
+#include <errno.h>
 #include <stdlib.h>
 #include <string.h>
 
@@ -14,7 +15,21 @@ static void test_setenv_getenv(void) {
   assert(strcmp(v, "replaced") == 0);
 }
 
+static void test_realpath(void) {
+  char buf[4096];
+  assert(realpath("/", buf) != NULL);
+  assert(strcmp(buf, "/") == 0);
+  char *p = realpath("/", NULL);
+  assert(p != NULL);
+  assert(strcmp(p, "/") == 0);
+  free(p);
+  errno = 0;
+  assert(realpath("/cpp2rust_definitely_missing", buf) == NULL);
+  assert(errno == ENOENT);
+}
+
 int main(void) {
   test_setenv_getenv();
+  test_realpath();
   return 0;
 }