diff --git a/arch/sim/src/sim/up_hostfs.c b/arch/sim/src/sim/up_hostfs.c
index 151799e58f..c3188c5946 100644
--- a/arch/sim/src/sim/up_hostfs.c
+++ b/arch/sim/src/sim/up_hostfs.c
@@ -181,6 +181,11 @@ int host_open(const char *pathname, int flags, nuttx_mode_t mode)
     }
 #endif
 
+  if (flags & NUTTX_O_CLOEXEC)
+    {
+      mapflags |= O_CLOEXEC;
+    }
+
   int ret = open(pathname, mapflags, mode);
   if (ret == -1)
     {
diff --git a/include/nuttx/fs/hostfs.h b/include/nuttx/fs/hostfs.h
index 499565b4c6..6773512ef4 100644
--- a/include/nuttx/fs/hostfs.h
+++ b/include/nuttx/fs/hostfs.h
@@ -84,6 +84,7 @@
 #define NUTTX_O_SYNC            (1 << 7)  /* Synchronize output on write */
 #define NUTTX_O_BINARY          (1 << 8)  /* Open the file in binary mode. */
 #define NUTTX_O_DIRECT          (1 << 9)  /* Avoid caching, write directly to hardware */
+#define NUTTX_O_CLOEXEC         (1 << 10) /* Close on execute */
 
 #define NUTTX_O_RDWR            (NUTTX_O_RDONLY | NUTTX_O_WRONLY)