diff --git a/homeassistant/components/apsystems/entity.py b/homeassistant/components/apsystems/entity.py
index 7770b451680..c3e67f52c82 100644
--- a/homeassistant/components/apsystems/entity.py
+++ b/homeassistant/components/apsystems/entity.py
@@ -19,10 +19,20 @@ class ApSystemsEntity(Entity):
         data: ApSystemsData,
     ) -> None:
         """Initialize the APsystems entity."""
+
+        # Handle device version safely
+        sw_version = None
+        if data.coordinator.device_version:
+            version_parts = data.coordinator.device_version.split(" ")
+            if len(version_parts) > 1:
+                sw_version = version_parts[1]
+            else:
+                sw_version = version_parts[0]
+
         self._attr_device_info = DeviceInfo(
             identifiers={(DOMAIN, data.device_id)},
             manufacturer="APsystems",
             model="EZ1-M",
             serial_number=data.device_id,
-            sw_version=data.coordinator.device_version.split(" ")[1],
+            sw_version=sw_version,
         )