diff --git a/build/build.go b/build/build.go
index 46eead92..10f3923f 100644
--- a/build/build.go
+++ b/build/build.go
@@ -1267,6 +1267,7 @@ func waitContextDeps(ctx context.Context, index int, results *waitmap.Map, so *c
 					so.FrontendAttrs["input-metadata:"+k+"::"+platform] = string(dt)
 				}
 			}
+			delete(so.FrontendAttrs, v)
 		}
 		if rr.Ref != nil {
 			st, err := rr.Ref.ToState()