diff --git a/src/ffx/ffx_controller.py b/src/ffx/ffx_controller.py
index cf6586d..f2a6633 100644
--- a/src/ffx/ffx_controller.py
+++ b/src/ffx/ffx_controller.py
@@ -112,7 +112,7 @@ class FfxController():
 
         self.__logger.debug(f"FfxController.generateOutputTokens(): base='{filePathBase}' format='{format}' ext='{ext}'")
 
-        outputFilePath = f"{filePathBase}{'.'+str(ext) if ext else ''}"
+        outputFilePath = f"{filePathBase}{('.'+str(ext)) if ext else ''}"
         if format:
             return ['-f', format, outputFilePath]
         else: