diff --git a/src/Umbraco.Examine/ExamineExtensions.cs b/src/Umbraco.Examine/ExamineExtensions.cs
index d231a86f69..fb4ad59898 100644
--- a/src/Umbraco.Examine/ExamineExtensions.cs
+++ b/src/Umbraco.Examine/ExamineExtensions.cs
@@ -27,7 +27,7 @@ namespace Umbraco.Examine
         /// <remarks>
         /// myFieldName_en-us will match the "en-us"
         /// </remarks>
-        internal static readonly Regex CultureIsoCodeFieldNameMatchExpression = new Regex("^([_\\w]+)_([a-z]{2}-[a-z0-9]{2,4})$", RegexOptions.Compiled);
+        internal static readonly Regex CultureIsoCodeFieldNameMatchExpression = new Regex("^(?<FieldName>[_\\w]+)_(?<CultureName>[a-z]{2,3}(-[a-z0-9]{2,4})?)$", RegexOptions.Compiled | RegexOptions.ExplicitCapture);
 
         private static bool _isConfigured = false;
         private static object _configuredInit = null;
@@ -67,7 +67,7 @@ namespace Umbraco.Examine
             foreach (var field in allFields)
             {
                 var match = CultureIsoCodeFieldNameMatchExpression.Match(field);
-                if (match.Success && match.Groups.Count == 3 && culture.InvariantEquals(match.Groups[2].Value))
+                if (match.Success && culture.InvariantEquals(match.Groups["CultureName"].Value))
                     yield return field;
             }
         }
@@ -85,7 +85,7 @@ namespace Umbraco.Examine
             foreach (var field in allFields)
             {
                 var match = CultureIsoCodeFieldNameMatchExpression.Match(field);
-                if (match.Success && match.Groups.Count == 3 && culture.InvariantEquals(match.Groups[2].Value))
+                if (match.Success && culture.InvariantEquals(match.Groups["CultureName"].Value))
                 {
                     yield return field; //matches this culture field
                 }
diff --git a/src/Umbraco.Examine/UmbracoFieldDefinitionCollection.cs b/src/Umbraco.Examine/UmbracoFieldDefinitionCollection.cs
index 1e7b51aa14..4d8409754a 100644
--- a/src/Umbraco.Examine/UmbracoFieldDefinitionCollection.cs
+++ b/src/Umbraco.Examine/UmbracoFieldDefinitionCollection.cs
@@ -73,13 +73,13 @@ namespace Umbraco.Examine
                 return true;
 
             //before we use regex to match do some faster simple matching since this is going to execute quite a lot
-            if (!fieldName.Contains("_") || !fieldName.Contains("-"))
+            if (!fieldName.Contains("_"))
                 return false;
 
             var match = ExamineExtensions.CultureIsoCodeFieldNameMatchExpression.Match(fieldName);
-            if (match.Success && match.Groups.Count == 3)
+            if (match.Success)
             {
-                var nonCultureFieldName = match.Groups[1].Value;
+                var nonCultureFieldName = match.Groups["FieldName"].Value;
                 //check if there's a definition for this and if so return the field definition for the culture field based on the non-culture field
                 if (base.TryGetValue(nonCultureFieldName, out var existingFieldDefinition))
                 {