diff --git a/server/parser/index.js b/server/parser/index.js
index 3a1e448..8db1e6c 100644
--- a/server/parser/index.js
+++ b/server/parser/index.js
@@ -39,10 +39,24 @@ export class Parser {
       const dayPlans = [];
       for (const plan of plans) {
         const foundPlan = dayPlans.find((e) => e.date == plan.date);
-        if (!foundPlan) dayPlans.push(plan);
-        else {
+        if (!foundPlan) {
+          // Make sure to not insert duplicate substitutions within a file
+          const changes = structuredClone(plan.changes);
+          const cleanedChanges = [];
+          for (const change of changes) {
+            const changeExists = cleanedChanges.find(
+              (e) => JSON.stringify(e) == JSON.stringify(change),
+            );
+            if (!changeExists) {
+              cleanedChanges.push(change);
+            }
+            // Use the new array of changes
+            plan.changes = cleanedChanges;
+          }
+          dayPlans.push(plan);
+        } else {
           for (const change of plan.changes) {
-            // Make sure to not insert the exact same substitution twice
+            // Make sure to not insert a substitution that already exists in the changes
             const changeExists = foundPlan.changes.find(
               (e) => JSON.stringify(e) == JSON.stringify(change),
             );