diff --git a/subsys/modbus/modbus_internal.h b/subsys/modbus/modbus_internal.h
index 080da58ea09..8b40f7c6476 100644
--- a/subsys/modbus/modbus_internal.h
+++ b/subsys/modbus/modbus_internal.h
@@ -88,6 +88,7 @@ struct modbus_serial_config {
 };
 
 #define MODBUS_STATE_CONFIGURED		0
+#define MODBUS_STATE_RX_ENABLED		1
 
 struct modbus_context {
 	/* Interface name */
diff --git a/subsys/modbus/modbus_serial.c b/subsys/modbus/modbus_serial.c
index d76ebff4cd9..2a96ac37b6a 100644
--- a/subsys/modbus/modbus_serial.c
+++ b/subsys/modbus/modbus_serial.c
@@ -50,6 +50,17 @@ static void modbus_serial_tx_off(struct modbus_context *ctx)
 	}
 }
 
+static void modbus_serial_rx_fifo_drain(struct modbus_context *ctx)
+{
+	struct modbus_serial_config *cfg = ctx->cfg;
+	uint8_t buf[8];
+	int n;
+
+	do {
+		n = uart_fifo_read(cfg->dev, buf, sizeof(buf));
+	} while (n == sizeof(buf));
+}
+
 static void modbus_serial_rx_on(struct modbus_context *ctx)
 {
 	struct modbus_serial_config *cfg = ctx->cfg;
@@ -58,6 +69,7 @@ static void modbus_serial_rx_on(struct modbus_context *ctx)
 		gpio_pin_set(cfg->re->port, cfg->re->pin, 1);
 	}
 
+	atomic_set_bit(&ctx->state, MODBUS_STATE_RX_ENABLED);
 	uart_irq_rx_enable(cfg->dev);
 }
 
@@ -66,6 +78,8 @@ static void modbus_serial_rx_off(struct modbus_context *ctx)
 	struct modbus_serial_config *cfg = ctx->cfg;
 
 	uart_irq_rx_disable(cfg->dev);
+	atomic_clear_bit(&ctx->state, MODBUS_STATE_RX_ENABLED);
+
 	if (cfg->re != NULL) {
 		gpio_pin_set(cfg->re->port, cfg->re->pin, 0);
 	}
@@ -312,6 +326,11 @@ static void cb_handler_rx(struct modbus_context *ctx)
 {
 	struct modbus_serial_config *cfg = ctx->cfg;
 
+	if (!atomic_test_bit(&ctx->state, MODBUS_STATE_RX_ENABLED)) {
+		modbus_serial_rx_fifo_drain(ctx);
+		return;
+	}
+
 	if ((ctx->mode == MODBUS_MODE_ASCII) &&
 	    IS_ENABLED(CONFIG_MODBUS_ASCII_MODE)) {
 		uint8_t c;
@@ -379,6 +398,7 @@ static void cb_handler_tx(struct modbus_context *ctx)
 		/* Disable transmission */
 		cfg->uart_buf_ptr = &cfg->uart_buf[0];
 		modbus_serial_tx_off(ctx);
+		modbus_serial_rx_fifo_drain(ctx);
 		modbus_serial_rx_on(ctx);
 	}
 }