diff --git a/arch/sim/src/sim/posix/sim_hostuart.c b/arch/sim/src/sim/posix/sim_hostuart.c
index 04254bc882848..a98410393ada0 100644
--- a/arch/sim/src/sim/posix/sim_hostuart.c
+++ b/arch/sim/src/sim/posix/sim_hostuart.c
@@ -95,6 +95,8 @@ static void restoremode(void)
 
 void host_uart_start(void)
 {
+  int nonblock = 1;
+
   /* Get the current stdin terminal mode */
 
   tcgetattr(0, &g_cooked);
@@ -103,6 +105,14 @@ void host_uart_start(void)
 
   setrawmode(0);
 
+  host_uninterruptible_no_return(ioctl, 0, FIONBIO, &nonblock);
+
+  /* Set stdout to non-blocking to prevent write(1, ...) from blocking
+   * the entire sim process when the host pipe buffer is full.
+   */
+
+  host_uninterruptible_no_return(ioctl, 1, FIONBIO, &nonblock);
+
   /* Restore the original terminal mode before exit */
 
   atexit(restoremode);