diff --git a/server/parser/index.js b/server/parser/index.js
index 0f508db..3a1e448 100644
--- a/server/parser/index.js
+++ b/server/parser/index.js
@@ -40,7 +40,17 @@ export class Parser {
       for (const plan of plans) {
         const foundPlan = dayPlans.find((e) => e.date == plan.date);
         if (!foundPlan) dayPlans.push(plan);
-        else foundPlan.changes.push(...plan.changes);
+        else {
+          for (const change of plan.changes) {
+            // Make sure to not insert the exact same substitution twice
+            const changeExists = foundPlan.changes.find(
+              (e) => JSON.stringify(e) == JSON.stringify(change),
+            );
+            if (!changeExists) {
+              foundPlan.changes.push(change);
+            }
+          }
+        }
       }
       // Insert substitutions of all substitution plans
       for (const plan of dayPlans) {