diff --git a/js/receipt-form.ts b/js/receipt-form.ts
index a2a6cae..30c29e2 100644
--- a/js/receipt-form.ts
+++ b/js/receipt-form.ts
@@ -30,6 +30,23 @@ const imgPreview = document.getElementById(
 ) as HTMLImageElement;
 const xactselect = document.getElementById("transactions") as SlSelect;
 
+let dirty = false;
+
+window.addEventListener("beforeunload", function(evt) {
+    if (dirty) {
+        evt.preventDefault();
+    }
+});
+
+form.querySelectorAll("sl-input, sl-textarea, input").forEach((inp) => {
+    let eventName = inp.tagName == "input" ? "cange" : "sl-change";
+    inp.addEventListener(eventName, (evt) => {
+        if ((evt.target as HTMLInputElement).value) {
+            dirty = true;
+        }
+    });
+});
+
 form.addEventListener("submit", async (evt) => {
     evt.preventDefault();
     btnSubmit.loading = true;
@@ -55,6 +72,7 @@ form.addEventListener("submit", async (evt) => {
     }
     if (r.ok) {
         notify("Successfully uploaded receipt", undefined, undefined, null);
+        dirty = false;
         window.location.href = "/receipts";
     } else {
         const err = await getResponseError(r);
@@ -62,6 +80,10 @@ form.addEventListener("submit", async (evt) => {
     }
 });
 
+form.addEventListener("reset", () => {
+    dirty = false;
+});
+
 cameraInput.addEventListener("ready", ((evt: CustomEvent) => {
     btnSubmit.disabled = !evt.detail.hasPhoto;
     btnUpload.disabled = !!evt.detail.hasPhoto;