diff --git a/arch/aarch64.c b/arch/aarch64.c
index f90935a..68a81a3 100644
--- a/arch/aarch64.c
+++ b/arch/aarch64.c
@@ -99,4 +99,32 @@ int32_t openat(int32_t fd, const char* filename, uint32_t flags, uint32_t mode)
   return (int32_t)rtn;
 }
 
+int close(unsigned int fd){
+  long int rtn;
+  asm ( 
+    "mov x0, %1\n"
+    "mov x8, #57\n"
+    "svc #0\n"
+    "mov %0, x0\n"
+    : "=r"(rtn)
+    : "r" ((long)fd)
+    : "x0", "x8"
+  );
+  return (int)rtn;
+}
+
+int fsync(unsigned int fd){
+  long int rtn;
+  asm ( 
+    "mov x0, %1\n"
+    "mov x8, #82\n"
+    "svc #0\n"
+    "mov %0, x0\n"
+    : "=r"(rtn)
+    : "r" ((long)fd)
+    : "x0", "x8"
+  );
+  return (int)rtn;
+}
+
 #endif
diff --git a/arch/mips.c b/arch/mips.c
index 10d43fa..91ca092 100644
--- a/arch/mips.c
+++ b/arch/mips.c
@@ -74,4 +74,32 @@ int32_t openat(int32_t fd, const char* filename, uint32_t flags, uint32_t mode)
   return file;
 }
 
+int close(unsigned int fd){
+  int rtn = 0;
+  asm ( 
+    "move $a0, %1\n"
+    "li $v0, 4006\n"
+    "syscall\n"
+    "move %0, $v0\n"
+    : "=r"(rtn)
+    : "r" (fd)
+    : "a0", "v0"
+  );
+  return rtn;
+}
+
+int fsync(unsigned int fd){
+  int rtn = 0;
+  asm ( 
+    "move $a0, %1\n"
+    "li $v0, 4118\n"
+    "syscall\n"
+    "move %0, $v0\n"
+    : "=r"(rtn)
+    : "r" (fd)
+    : "a0", "v0"
+  );
+  return rtn;
+}
+
 #endif
diff --git a/arch/x86_64.c b/arch/x86_64.c
index 1212137..6016171 100644
--- a/arch/x86_64.c
+++ b/arch/x86_64.c
@@ -64,4 +64,28 @@ int32_t openat(int32_t fd, const char* filename, uint32_t flags, uint32_t mode)
   return file;
 }
 
+#define SYS_CLOSE 3
+int close(unsigned int fd) {
+  int rtn;
+  asm volatile(
+    "syscall"
+    : "=a"(rtn)
+    : "a"(SYS_CLOSE), "D"(fd)
+    : "rcx", "r11"
+  );
+  return rtn;
+}
+
+#define SYS_FSYNC 74
+int fsync(unsigned int fd) {
+  int rtn;
+  asm volatile(
+    "syscall"
+    : "=a"(rtn)
+    : "a"(SYS_FSYNC), "D"(fd)
+    : "rcx", "r11"
+  );
+  return rtn;
+}
+
 #endif /* ifdef __x86_64__ */
diff --git a/buildtest.c b/buildtest.c
index 3ae2429..17bed6c 100644
--- a/buildtest.c
+++ b/buildtest.c
@@ -35,6 +35,8 @@ int main() {
   write(STDOUT, input_buffer, n_read);
   if(fout > 0) {
     write(fout, input_buffer, n_read);
+    fsync(fout);
+    close(fout);
   }
 
   // Test the open syscall
diff --git a/sys.h b/sys.h
index 2bce1db..e3bed1d 100644
--- a/sys.h
+++ b/sys.h
@@ -32,6 +32,8 @@ intptr_t read(int32_t fd, const void* buf, intptr_t size);
 int32_t openat(int32_t fd, const char* filename, uint32_t flags, uint32_t mode);
 #define open(...) openat(AT_FDCWD, __VA_ARGS__, 0)
 #define openc(...) openat(AT_FDCWD, __VA_ARGS__)
+int close(unsigned int fd);
+int fsync(unsigned int fd);
 
 uint32_t fork();