--- a/toolkit/components/crashes/CrashManager.jsm
+++ b/toolkit/components/crashes/CrashManager.jsm
@@ -427,23 +427,23 @@ this.CrashManager.prototype = Object.fre
       yield store.save();
     }
   }),
 
   /**
    * Set the classification of a crash.
    *
    * @param crashID (string) Crash ID. Likely a UUID.
-   * @param classification (string) Crash classification/reason.
+   * @param classifications (array) Crash classifications.
    *
-   * @return boolean True if the classification was recorded and false if not.
+   * @return boolean True if the data was recorded and false if not.
    */
-  setCrashClassification: Task.async(function* (crashID, classification) {
+  setCrashClassifications: Task.async(function* (crashID, classifications) {
     let store = yield this._getStore();
-    if (store.setCrashClassification(crashID, classification)) {
+    if (store.setCrashClassifications(crashID, classifications)) {
       yield store.save();
     }
   }),
 
   /**
    * Obtain the paths of all unprocessed events files.
    *
    * The promise-resolved array is sorted by file mtime, oldest to newest.
@@ -1077,17 +1077,17 @@ CrashStore.prototype = Object.freeze({
       }
 
       this._data.crashes.set(id, {
         id: id,
         remoteID: null,
         type: type,
         crashDate: date,
         submissions: new Map(),
-        classification: null,
+        classifications: [],
       });
     }
 
     let crash = this._data.crashes.get(id);
     crash.type = type;
     crash.crashDate = date;
 
     return crash;
@@ -1188,25 +1188,25 @@ CrashStore.prototype = Object.freeze({
     }
 
     submission.responseDate = date;
     submission.result = result;
     return true;
   },
 
   /**
-   * @return boolean True if the classification was set.
+   * @return boolean True if the classifications were set.
    */
-  setCrashClassification: function (crashID, classification) {
+  setCrashClassifications: function (crashID, classifications) {
     let crash = this._data.crashes.get(crashID);
     if (!crash) {
       return false;
     }
 
-    crash.classification = classification;
+    crash.classifications = classifications;
     return true;
   },
 });
 
 /**
  * Represents an individual crash with metadata.
  *
  * This is a wrapper around the low-level anonymous JS objects that define
@@ -1257,18 +1257,18 @@ CrashRecord.prototype = Object.freeze({
   isOfType: function (processType, crashType) {
     return processType + "-" + crashType == this.type;
   },
 
   get submissions() {
     return this._o.submissions;
   },
 
-  get classification() {
-    return this._o.classification;
+  get classifications() {
+    return this._o.classifications;
   },
 });
 
 /**
  * Obtain the global CrashManager instance used by the running application.
  *
  * CrashManager is likely only ever instantiated once per application lifetime.
  * The main reason it's implemented as a reusable type is to facilitate testing.

--- a/toolkit/components/crashes/tests/xpcshell/test_crash_manager.js
+++ b/toolkit/components/crashes/tests/xpcshell/test_crash_manager.js
@@ -400,23 +400,24 @@ add_task(function* test_addSubmissionAtt
 
   let submission = submissions.get("submission");
   Assert.ok(!!submission);
   Assert.equal(submission.requestDate.getTime(), DUMMY_DATE.getTime());
   Assert.equal(submission.responseDate.getTime(), DUMMY_DATE_2.getTime());
   Assert.equal(submission.result, m.SUBMISSION_RESULT_OK);
 });
 
-add_task(function* test_setCrashClassification() {
+add_task(function* test_setCrashClassifications() {
   let m = yield getManager();
 
   yield m.addCrash(m.PROCESS_TYPE_MAIN, m.CRASH_TYPE_CRASH,
                    "main-crash", DUMMY_DATE);
-  yield m.setCrashClassification("main-crash", "class");
-  Assert.equal((yield m.getCrashes())[0].classification, "class");
+  yield m.setCrashClassifications("main-crash", ["a"]);
+  let classifications = (yield m.getCrashes())[0].classifications;
+  Assert.ok(classifications.indexOf("a") != -1);
 });
 
 add_task(function* test_setRemoteCrashID() {
   let m = yield getManager();
 
   yield m.addCrash(m.PROCESS_TYPE_MAIN, m.CRASH_TYPE_CRASH,
                    "main-crash", DUMMY_DATE);
   yield m.setRemoteCrashID("main-crash", "bp-1");

--- a/toolkit/components/crashes/tests/xpcshell/test_crash_store.js
+++ b/toolkit/components/crashes/tests/xpcshell/test_crash_store.js
@@ -566,20 +566,25 @@ add_task(function* test_convertSubmissio
   Assert.equal(submission.responseDate.getTime(), DUMMY_DATE_2.getTime());
 });
 
 add_task(function* test_setCrashClassification() {
   let s = yield getStore();
 
   Assert.ok(s.addCrash(PROCESS_TYPE_MAIN, CRASH_TYPE_CRASH, "crash1",
                        new Date()));
-  Assert.equal(s.crashes[0].classification, null);
+  let classifications = s.crashes[0].classifications;
+  Assert.ok(!!classifications);
+  Assert.equal(classifications.length, 0);
 
-  Assert.ok(s.setCrashClassification("crash1", "foo"));
-  Assert.equal(s.crashes[0].classification, "foo");
+  Assert.ok(s.setCrashClassifications("crash1", ["foo", "bar"]));
+  classifications = s.crashes[0].classifications;
+  Assert.equal(classifications.length, 2);
+  Assert.ok(classifications.indexOf("foo") != -1);
+  Assert.ok(classifications.indexOf("bar") != -1);
 });
 
 add_task(function* test_setRemoteCrashID() {
   let s = yield getStore();
 
   Assert.ok(s.addCrash(PROCESS_TYPE_MAIN, CRASH_TYPE_CRASH, "crash1",
                        new Date()));
   Assert.equal(s.crashes[0].remoteID, null);