diff --git a/OscCommentMacroListener.py b/OscCommentMacroListener.py
index 296d461..699c089 100644
--- a/OscCommentMacroListener.py
+++ b/OscCommentMacroListener.py
@@ -237,6 +237,7 @@ class OscCommentMacroListener(CommentMacroListener):
         ctx.targets = []
 
     def exitMaster(self, ctx: CommentMacroParser.MasterContext):
+        ctx.targets = set(ctx.targets)  # no duplicates
         if isinstance(ctx.parentCtx, CommentMacroParser.MacroContext):
             ctx.parentCtx.master = ctx
 
@@ -264,4 +265,5 @@ class OscCommentMacroListener(CommentMacroListener):
         ctx.targets = []
 
     def exitTarget(self, ctx: CommentMacroParser.TargetContext):
+        ctx.target = set(ctx.targets)   # no duplicates
         ctx.parentCtx.targets.extend(ctx.targets)