diff --git a/chrome/content/zotero/xpcom/schema.js b/chrome/content/zotero/xpcom/schema.js
index 4d14a1868b..3c29ffd42c 100644
--- a/chrome/content/zotero/xpcom/schema.js
+++ b/chrome/content/zotero/xpcom/schema.js
@@ -3064,6 +3064,10 @@ Zotero.Schema = new function(){
 				Zotero.wait();
 			}
 			
+			// TODO
+			//
+			// Replace customBaseFieldMappings to fix FK fields/customField -> customFields->customFieldID
+			
 			_updateDBVersion('userdata', toVersion);
 			
 			Zotero.DB.commitTransaction();
diff --git a/userdata.sql b/userdata.sql
index 6f71b03bf7..be427bf56a 100644
--- a/userdata.sql
+++ b/userdata.sql
@@ -378,7 +378,7 @@ CREATE TABLE customBaseFieldMappings (
     PRIMARY KEY (customItemTypeID, baseFieldID, customFieldID),
     FOREIGN KEY (customItemTypeID) REFERENCES customItemTypes(customItemTypeID),
     FOREIGN KEY (baseFieldID) REFERENCES fields(fieldID),
-    FOREIGN KEY (customFieldID) REFERENCES fields(customFieldID)
+    FOREIGN KEY (customFieldID) REFERENCES customFields(customFieldID)
 );
 CREATE INDEX customBaseFieldMappings_baseFieldID ON customBaseFieldMappings(baseFieldID);
 CREATE INDEX customBaseFieldMappings_customFieldID ON customBaseFieldMappings(customFieldID);