diff --git a/src/NzbDrone.Common.Test/Http/HttpUriFixture.cs b/src/NzbDrone.Common.Test/Http/HttpUriFixture.cs
index f47c59881..d25d07bfe 100644
--- a/src/NzbDrone.Common.Test/Http/HttpUriFixture.cs
+++ b/src/NzbDrone.Common.Test/Http/HttpUriFixture.cs
@@ -10,6 +10,7 @@ namespace NzbDrone.Common.Test.Http
         [TestCase("abc://my_host.com:8080/root/api/")]
         [TestCase("abc://my_host.com:8080//root/api/")]
         [TestCase("abc://my_host.com:8080/root//api/")]
+        [TestCase("abc://[::1]:8080/root//api/")]
         public void should_parse(string uri)
         {
             var newUri = new HttpUri(uri);
diff --git a/src/NzbDrone.Common/Extensions/StringExtensions.cs b/src/NzbDrone.Common/Extensions/StringExtensions.cs
index 21729f6f8..6b6f04b8e 100644
--- a/src/NzbDrone.Common/Extensions/StringExtensions.cs
+++ b/src/NzbDrone.Common/Extensions/StringExtensions.cs
@@ -398,5 +398,10 @@ namespace NzbDrone.Common.Extensions
 
             return parsedAddress.AddressFamily == AddressFamily.InterNetwork || parsedAddress.AddressFamily == AddressFamily.InterNetworkV6;
         }
+
+        public static string ToUrlHost(this string input)
+        {
+            return input.Contains(":") ? $"[{input}]" : input;
+        }
     }
 }
diff --git a/src/NzbDrone.Common/Http/HttpUri.cs b/src/NzbDrone.Common/Http/HttpUri.cs
index f90e564f5..647da04ee 100644
--- a/src/NzbDrone.Common/Http/HttpUri.cs
+++ b/src/NzbDrone.Common/Http/HttpUri.cs
@@ -8,7 +8,7 @@ namespace NzbDrone.Common.Http
 {
     public class HttpUri : IEquatable<HttpUri>
     {
-        private static readonly Regex RegexUri = new Regex(@"^(?:(?<scheme>[a-z]+):)?(?://(?<host>[-_A-Z0-9.]+)(?::(?<port>[0-9]{1,5}))?)?(?<path>(?:(?:(?<=^)|/+)[^/?#\r\n]+)+/*|/+)?(?:\?(?<query>[^#\r\n]*))?(?:\#(?<fragment>.*))?$", RegexOptions.Compiled | RegexOptions.IgnoreCase);
+        private static readonly Regex RegexUri = new Regex(@"^(?:(?<scheme>[a-z]+):)?(?://(?<host>[-_A-Z0-9.]+|\[[[A-F0-9:]+\])(?::(?<port>[0-9]{1,5}))?)?(?<path>(?:(?:(?<=^)|/+)[^/?#\r\n]+)+/*|/+)?(?:\?(?<query>[^#\r\n]*))?(?:\#(?<fragment>.*))?$", RegexOptions.Compiled | RegexOptions.IgnoreCase);
 
         private readonly string _uri;
         public string FullUri => _uri;
@@ -70,6 +70,8 @@ namespace NzbDrone.Common.Http
 
         private void Parse()
         {
+            var parseSuccess = Uri.TryCreate(_uri, UriKind.RelativeOrAbsolute, out var uri);
+
             var match = RegexUri.Match(_uri);
 
             var scheme = match.Groups["scheme"];
@@ -79,7 +81,7 @@ namespace NzbDrone.Common.Http
             var query = match.Groups["query"];
             var fragment = match.Groups["fragment"];
 
-            if (!match.Success || (scheme.Success && !host.Success && path.Success))
+            if (!parseSuccess || (scheme.Success && !host.Success && path.Success))
             {
                 throw new ArgumentException("Uri didn't match expected pattern: " + _uri);
             }
diff --git a/src/NzbDrone.Core/Validation/RuleBuilderExtensions.cs b/src/NzbDrone.Core/Validation/RuleBuilderExtensions.cs
index b5e6f3be9..aa416ac1d 100644
--- a/src/NzbDrone.Core/Validation/RuleBuilderExtensions.cs
+++ b/src/NzbDrone.Core/Validation/RuleBuilderExtensions.cs
@@ -1,11 +1,15 @@
+using System;
 using System.Text.RegularExpressions;
 using FluentValidation;
 using FluentValidation.Validators;
+using NzbDrone.Common.Extensions;
 
 namespace NzbDrone.Core.Validation
 {
     public static class RuleBuilderExtensions
     {
+        private static readonly Regex HostRegex = new Regex("^[-_a-z0-9.]+$", RegexOptions.IgnoreCase | RegexOptions.Compiled);
+
         public static IRuleBuilderOptions<T, int> ValidId<T>(this IRuleBuilder<T, int> ruleBuilder)
         {
             return ruleBuilder.SetValidator(new GreaterThanValidator(0));
@@ -24,13 +28,15 @@ namespace NzbDrone.Core.Validation
         public static IRuleBuilderOptions<T, string> ValidHost<T>(this IRuleBuilder<T, string> ruleBuilder)
         {
             ruleBuilder.SetValidator(new NotEmptyValidator(null));
-            return ruleBuilder.SetValidator(new RegularExpressionValidator("^[-_a-z0-9.]+$", RegexOptions.IgnoreCase)).WithMessage("must be valid Host without http://");
+
+            return ruleBuilder.Must(x => HostRegex.IsMatch(x) || x.IsValidIpAddress()).WithMessage("must be valid Host without http://");
         }
 
         public static IRuleBuilderOptions<T, string> ValidRootUrl<T>(this IRuleBuilder<T, string> ruleBuilder)
         {
             ruleBuilder.SetValidator(new NotEmptyValidator(null));
-            return ruleBuilder.SetValidator(new RegularExpressionValidator("^https?://[-_a-z0-9.]+", RegexOptions.IgnoreCase)).WithMessage("must be valid URL that starts with http(s)://");
+
+            return ruleBuilder.Must(x => x.IsValidUrl() && x.StartsWith("http", StringComparison.InvariantCultureIgnoreCase)).WithMessage("must be valid URL that starts with http(s)://");
         }
 
         public static IRuleBuilderOptions<T, string> ValidUrlBase<T>(this IRuleBuilder<T, string> ruleBuilder, string example = "/readarr")