diff --git a/toolkit/components/crashes/CrashManager.jsm b/toolkit/components/crashes/CrashManager.jsm
index 473325939e2d..e5ef41308403 100644
--- a/toolkit/components/crashes/CrashManager.jsm
+++ b/toolkit/components/crashes/CrashManager.jsm
@@ -706,6 +706,18 @@ CrashStore.prototype = Object.freeze({
   // ceiling on the per-type/per-day records that will be stored.
   HIGH_WATER_DAILY_THRESHOLD: 100,
 
+  /**
+   * Reset all data.
+   */
+  reset() {
+    this._data = {
+      v: 1,
+      crashes: new Map(),
+      corruptDate: null,
+    };
+    this._countsByDay = new Map();
+  },
+
   /**
    * Load data from disk.
    *
@@ -713,13 +725,8 @@ CrashStore.prototype = Object.freeze({
    */
   load: function () {
     return Task.spawn(function* () {
-      // Loading replaces data. So reset data structures.
-      this._data = {
-        v: 1,
-        crashes: new Map(),
-        corruptDate: null,
-      };
-      this._countsByDay = new Map();
+      // Loading replaces data.
+      this.reset();
 
       try {
         let decoder = new TextDecoder();
diff --git a/toolkit/components/crashes/tests/xpcshell/test_crash_store.js b/toolkit/components/crashes/tests/xpcshell/test_crash_store.js
index 9f86c2d45793..3ff06f60c3e7 100644
--- a/toolkit/components/crashes/tests/xpcshell/test_crash_store.js
+++ b/toolkit/components/crashes/tests/xpcshell/test_crash_store.js
@@ -79,6 +79,15 @@ add_task(function test_add_crash() {
   Assert.equal(s.crashesCount, 2);
 });
 
+add_task(function test_reset() {
+  let s = yield getStore();
+
+  Assert.ok(s.addCrash(PROCESS_TYPE_MAIN, CRASH_TYPE_CRASH, "id1", DUMMY_DATE));
+  Assert.equal(s.crashes.length, 1);
+  s.reset();
+  Assert.equal(s.crashes.length, 0);
+});
+
 add_task(function test_save_load() {
   let s = yield getStore();