diff --git a/platformio/builder/tools/piobuild.py b/platformio/builder/tools/piobuild.py
index 69359a32..32a744e3 100644
--- a/platformio/builder/tools/piobuild.py
+++ b/platformio/builder/tools/piobuild.py
@@ -346,7 +346,7 @@ def BuildSources(env, variant_dir, src_dir, src_filter=None):
             "Error: The main program is already constructed and the inline "
             "source files are not allowed. Please use `env.BuildLibrary(...)` "
             "or PRE-type script instead."
-            )
+        )
         env.Exit(1)
 
     nodes = env.CollectBuildFiles(variant_dir, src_dir, src_filter)