diff --git a/CHANGELOG.md b/CHANGELOG.md
index 73e80139e..8d5ed2787 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -14,6 +14,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Changed
 
 - Improved the routes of the tabs
+- Enforced a stricter date format in the activities import: `dd-MM-yyyy` instead of `dd-MM-yy`
 - Updated the URL of the Ghostfolio Slack channel
 - Removed the _Ghostfolio in Numbers_ section from the about page
 
diff --git a/apps/client/src/app/services/import-activities.service.ts b/apps/client/src/app/services/import-activities.service.ts
index 06d33456c..21ee38274 100644
--- a/apps/client/src/app/services/import-activities.service.ts
+++ b/apps/client/src/app/services/import-activities.service.ts
@@ -223,11 +223,17 @@ export class ImportActivitiesService {
 
     for (const key of ImportActivitiesService.DATE_KEYS) {
       if (item[key]) {
-        if (isMatch(item[key], 'dd-MM-yyyy')) {
+        if (isMatch(item[key], 'dd-MM-yyyy') && item[key].length === '10') {
+          // Check length to only match yyyy (and not yy)
           date = parse(item[key], 'dd-MM-yyyy', new Date()).toISOString();
-        } else if (isMatch(item[key], 'dd/MM/yyyy')) {
+        } else if (
+          isMatch(item[key], 'dd/MM/yyyy') &&
+          item[key].length === '10'
+        ) {
+          // Check length to only match yyyy (and not yy)
           date = parse(item[key], 'dd/MM/yyyy', new Date()).toISOString();
-        } else if (isMatch(item[key], 'yyyyMMdd')) {
+        } else if (isMatch(item[key], 'yyyyMMdd') && item[key].length === '8') {
+          // Check length to only match yyyy (and not yy)
           date = parse(item[key], 'yyyyMMdd', new Date()).toISOString();
         } else {
           try {
diff --git a/test/import/invalid-date-yy.csv b/test/import/invalid-date-yy.csv
new file mode 100644
index 000000000..4bfa891e5
--- /dev/null
+++ b/test/import/invalid-date-yy.csv
@@ -0,0 +1,2 @@
+Date,Code,Currency,Price,Quantity,Action,Fee
+16/09/21,MSFT,USD,298.580,5,buy,19.00