diff --git a/resource/bluebird.js b/resource/bluebird.js
index e59988d1e..881f0820d 100644
--- a/resource/bluebird.js
+++ b/resource/bluebird.js
@@ -96,13 +96,10 @@
 	});
 	// TEMP: Only turn on if debug logging enabled?
 	Promise.onPossiblyUnhandledRejection(function (e, promise) {
-		if (e.name == 'ZoteroPromiseInterrupt') {
+		if (e.name == 'ZoteroPromiseInterrupt' || e.handledRejection) {
 			return;
 		}
 	
-		// Ignore some errors during tests
-		if (e.message && e.message.indexOf(' -- ignore') != -1) return;
-		
 		self.debug('Possibly unhandled rejection:\n\n' + e.message);
 		throw e;
 	});
diff --git a/resource/concurrentCaller.js b/resource/concurrentCaller.js
index e4155eb60..34861b44a 100644
--- a/resource/concurrentCaller.js
+++ b/resource/concurrentCaller.js
@@ -246,6 +246,7 @@ ConcurrentCaller.prototype._processNext = function () {
 			this._processNext();
 		});
 		
+		e.handledRejection = true;
 		f.deferred.reject(e);
 	});
 	return true;
diff --git a/test/tests/concurrentCallerTest.js b/test/tests/concurrentCallerTest.js
index 1cea84602..caa3b2d9d 100644
--- a/test/tests/concurrentCallerTest.js
+++ b/test/tests/concurrentCallerTest.js
@@ -206,8 +206,10 @@ describe("ConcurrentCaller", function () {
 						Zotero.debug("Throwing " + id);
 						// This causes an erroneous "possibly unhandled rejection" message in
 						// Bluebird 2.10.2 that I can't seem to get rid of (and the rejection
-						// is later handled), so pass " -- ignore" to tell Bluebird to ignore it
-						throw new Error("Fail -- ignore");
+						// is later handled), so tell Bluebird to ignore it
+						let e = new Error("Fail");
+						e.handledRejection = true;
+						throw e;
 					}
 					if (running > numConcurrent) {
 						failed = true;
@@ -279,8 +281,10 @@ describe("ConcurrentCaller", function () {
 						Zotero.debug("Throwing " + id);
 						// This causes an erroneous "possibly unhandled rejection" message in
 						// Bluebird 2.10.2 that I can't seem to get rid of (and the rejection
-						// is later handled), so pass " -- ignore" to tell Bluebird to ignore it
-						throw new Error("Fail -- ignore");
+						// is later handled), so tell Bluebird to ignore it
+						let e = new Error("Fail");
+						e.handledRejection = true;
+						throw e;
 					}
 					if (running > numConcurrent) {
 						failed = true;