diff --git a/bundles/org.openhab.binding.modbus.sungrow/README.md b/bundles/org.openhab.binding.modbus.sungrow/README.md
index 79a87f2cf34..70fed444c30 100644
--- a/bundles/org.openhab.binding.modbus.sungrow/README.md
+++ b/bundles/org.openhab.binding.modbus.sungrow/README.md
@@ -41,7 +41,7 @@ If you are using a Modbus TCP Slave and the WiNet-S Communication Module please
 - that the white list is disabled or your openHAB instance IP is listed
 
 Enabling modbus and whitelist setting can be done in WiNet-S Web-UI as shown below:
-<img src="./doc/WiNet-S_Modbus.PNG" alt="WiNet-S Modbus configuration"/>
+<img src="./doc/WiNet-S_Modbus.png" alt="WiNet-S Modbus configuration"/>
 
 ## Thing Configuration
 
diff --git a/bundles/org.openhab.binding.modbus.sungrow/doc/WiNet-S_Modbus.PNG b/bundles/org.openhab.binding.modbus.sungrow/doc/WiNet-S_Modbus.png
similarity index 100%
rename from bundles/org.openhab.binding.modbus.sungrow/doc/WiNet-S_Modbus.PNG
rename to bundles/org.openhab.binding.modbus.sungrow/doc/WiNet-S_Modbus.png