1 files changed, 2 insertions, 0 deletions
diff --git a/build.py b/build.py
index 7b05f19..3cce771 100644
--- a/build.py
+++ b/build.py
@@ -742,6 +742,8 @@ class CustomTarget:
         else:
             self.install = False
         self.build_always = kwargs.get('build_always', False)
+        if not isinstance(self.build_always, bool):
+            raise InvalidArguments('Argument build_always must be a boolean.')
 
     def get_basename(self):
         return self.name