diff --git a/chrome/content/zotero/import/mendeley/mendeleyImport.js b/chrome/content/zotero/import/mendeley/mendeleyImport.js
index 1e54e233c7..7c37816f5b 100644
--- a/chrome/content/zotero/import/mendeley/mendeleyImport.js
+++ b/chrome/content/zotero/import/mendeley/mendeleyImport.js
@@ -1241,7 +1241,7 @@ Zotero_Import_Mendeley.prototype._makeCreator = function (creatorType, firstName
 Zotero_Import_Mendeley.prototype._addExtraField = function (extra, field, val) {
 	// Strip the field if it appears at the beginning of the value (to avoid "DOI: DOI: 10...")
 	if (typeof val == 'string') {
-		val = val.replace(new RegExp(`^${field}:\s*`, 'i'), "");
+		val = val.replace(new RegExp(`^${field}:\\s*`, 'i'), "");
 	}
 	extra = extra ? extra + '\n' : '';
 	if (field != 'arXiv') {
diff --git a/test/tests/data/mendeleyMock/items-simple.json b/test/tests/data/mendeleyMock/items-simple.json
index 997edbe792..ff3aa22494 100644
--- a/test/tests/data/mendeleyMock/items-simple.json
+++ b/test/tests/data/mendeleyMock/items-simple.json
@@ -14,7 +14,7 @@
         "identifiers":
         {
             "doi": "10.1111",
-            "pmid": "11111111",
+            "pmid": "PMID:    11111111",
             "arxiv": "1111.2222"
         },
         "starred": false,
diff --git a/test/tests/mendeleyImportTest.js b/test/tests/mendeleyImportTest.js
index 796a34cd2e..a4b65ff887 100644
--- a/test/tests/mendeleyImportTest.js
+++ b/test/tests/mendeleyImportTest.js
@@ -174,8 +174,7 @@ describe('Zotero_Import_Mendeley', function () {
 
 			// identifiers
 			assert.equal(journal.getField('DOI'), '10.1111');
-			assert.include(journal.getField('extra'), 'PMID: 11111111');
-			assert.include(journal.getField('extra'), 'arXiv: 1111.2222');
+			assert.sameMembers(journal.getField('extra').split('\n'), ['PMID: 11111111', 'arXiv: 1111.2222']);
 
 			// attachment & annotations
 			assert.lengthOf(withpdf.getAttachments(), 1);