diff --git a/drivers/watchdog/wdt_iwdg_stm32.c b/drivers/watchdog/wdt_iwdg_stm32.c
index d936f640a64..c13d3f77e57 100644
--- a/drivers/watchdog/wdt_iwdg_stm32.c
+++ b/drivers/watchdog/wdt_iwdg_stm32.c
@@ -77,7 +77,7 @@ static void iwdg_stm32_convert_timeout(uint32_t timeout,
 
 static int iwdg_stm32_setup(const struct device *dev, uint8_t options)
 {
-	IWDG_TypeDef *iwdg = IWDG_STM32_STRUCT(dev);
+	ARG_UNUSED(dev);
 
 	/* Deactivate running when debugger is attached. */
 	if (options & WDT_OPT_PAUSE_HALTED_BY_DBG) {
@@ -99,7 +99,7 @@ static int iwdg_stm32_setup(const struct device *dev, uint8_t options)
 		return -ENOTSUP;
 	}
 
-	LL_IWDG_Enable(iwdg);
+	/* Enable the IWDG only when the timeout is installed */
 	return 0;
 }
 
@@ -134,6 +134,7 @@ static int iwdg_stm32_install_timeout(const struct device *dev,
 
 	tickstart = k_uptime_get_32();
 
+	LL_IWDG_Enable(iwdg);
 	LL_IWDG_EnableWriteAccess(iwdg);
 
 	LL_IWDG_SetPrescaler(iwdg, prescaler);
@@ -172,12 +173,10 @@ static const struct wdt_driver_api iwdg_stm32_api = {
 static int iwdg_stm32_init(const struct device *dev)
 {
 #ifndef CONFIG_WDT_DISABLE_AT_BOOT
-	IWDG_TypeDef *iwdg = IWDG_STM32_STRUCT(dev);
 	struct wdt_timeout_cfg config = {
 		.window.max = CONFIG_IWDG_STM32_INITIAL_TIMEOUT
 	};
 
-	LL_IWDG_Enable(iwdg);
 	iwdg_stm32_install_timeout(dev, &config);
 #endif