diff --git a/src/Config.Tests/ConfigurationTests.cs b/src/Config.Tests/ConfigurationTests.cs
index 784a9ba..5eb5e58 100644
--- a/src/Config.Tests/ConfigurationTests.cs
+++ b/src/Config.Tests/ConfigurationTests.cs
@@ -1,5 +1,8 @@
-using System.Globalization;
+using System;
+using System.Globalization;
 using System.IO;
+using System.Reflection;
+using System.Runtime.CompilerServices;
 using Microsoft.Extensions.Configuration;
 using Xunit;
 using Xunit.Abstractions;
@@ -15,33 +18,50 @@ public ConfigurationTests(ITestOutputHelper output)
             Config.GlobalLocation = Path.Combine(Constants.CurrentDirectory, "Content", "global.netconfig");
             Config.SystemLocation = Path.Combine(Constants.CurrentDirectory, "Content", "system.netconfig");
             CultureInfo.CurrentCulture = CultureInfo.InvariantCulture;
-            Directory.SetCurrentDirectory(Path.Combine(Constants.CurrentDirectory, "Content", "web"));
             this.output = output;
         }
 
-        [FlakyFact]
+        [Fact]
         public void can_load_hierarchical_values()
         {
-            var config = new ConfigurationBuilder().AddDotNetConfig().Build();
+            var config = BuildConfiguration();
+
             Assert.Equal("on", config["core:parent"]);
             Assert.Equal("true", config["http:sslVerify"]);
             Assert.Equal("false", config["http:https://weak.example.com:sslVerify"]);
             Assert.Equal("yay", config["foo:bar:baz"]);
         }
 
-        [FlakyFact]
+        [Fact]
         public void can_save_values()
         {
-            var config = new ConfigurationBuilder().AddDotNetConfig().Build();
+            var config = BuildConfiguration();
+
             config["foo:enabled"] = "true";
             config["foo:bar:baz"] = "bye";
             config["http:https://weaker.example.com:sslVerify"] = "false";
 
-            var dotnet = Config.Build();
+            var dotnet = Config.Build(Path.Combine(Constants.CurrentDirectory, "Content", "web", nameof(can_save_values)));
 
             Assert.Equal("true", dotnet.GetString("foo", "enabled"));
             Assert.Equal("bye", dotnet.GetString("foo", "bar", "baz"));
             Assert.Equal("false", dotnet.GetString("http", "https://weaker.example.com", "sslVerify"));
         }
+
+        [Fact]
+        public void local_values_override_system_values()
+        {
+            var config = BuildConfiguration();
+
+            Assert.Equal("123", config["local:value"]);
+        }
+
+        IConfiguration BuildConfiguration([CallerMemberName] string? methodName = null)
+        {
+            var dir = Path.Combine(Constants.CurrentDirectory, "Content", "web", methodName);
+            Directory.CreateDirectory(dir);
+
+            return new ConfigurationBuilder().AddDotNetConfig(dir).Build();
+        }
     }
 }
\ No newline at end of file
diff --git a/src/Config.Tests/Content/global.netconfig b/src/Config.Tests/Content/global.netconfig
index 2adff22..458ffc7 100644
--- a/src/Config.Tests/Content/global.netconfig
+++ b/src/Config.Tests/Content/global.netconfig
@@ -2,3 +2,5 @@
 	sslVerify = false
 [core]
     global = yes
+[local]
+    value = 456
\ No newline at end of file
diff --git a/src/Config.Tests/Content/web/.netconfig b/src/Config.Tests/Content/web/.netconfig
index 5f28270..54f9119 100644
--- a/src/Config.Tests/Content/web/.netconfig
+++ b/src/Config.Tests/Content/web/.netconfig
@@ -1 +1,2 @@
-
\ No newline at end of file
+[local]
+    value = 123
\ No newline at end of file
diff --git a/src/Configuration/DotNetConfigExtensions.cs b/src/Configuration/DotNetConfigExtensions.cs
index 53c5366..d140179 100644
--- a/src/Configuration/DotNetConfigExtensions.cs
+++ b/src/Configuration/DotNetConfigExtensions.cs
@@ -22,6 +22,25 @@ public static class DotNetConfigExtensions
         /// </code>
         /// </remarks>
         public static IConfigurationBuilder AddDotNetConfig(this IConfigurationBuilder builder)
-            => builder.Add(new DotNetConfigSource());
+            => AddDotNetConfig(builder, null);
+
+        /// <summary>
+        /// Adds the DotNetConfig configuration provider to the <paramref name="builder"/>.
+        /// </summary>
+        /// <param name="builder">The <see cref="IConfigurationBuilder"/> to add dotnet config support to.</param>
+        /// <param name="path">Optional path to use when building the configuration. See <see cref="Config.Build(string?)"/>. 
+        /// If not provided, the current directory will be used.</param>
+        /// <returns>The <see cref="IConfigurationBuilder"/>.</returns>
+        /// <remarks>
+        /// Simply invoke this method on a builder to add hierarchical dotnet-config support 
+        /// to your app, for example:
+        /// <code>
+        /// var config = new ConfigurationBuilder().AddDotNetConfig().Build();
+        /// 
+        /// var ssl = config["http:sslVerify"];
+        /// </code>
+        /// </remarks>
+        public static IConfigurationBuilder AddDotNetConfig(this IConfigurationBuilder builder, string? path = null)
+            => builder.Add(new DotNetConfigSource(path));
     }
 }
diff --git a/src/Configuration/DotNetConfigProvider.cs b/src/Configuration/DotNetConfigProvider.cs
index d4cf22b..85f25c3 100644
--- a/src/Configuration/DotNetConfigProvider.cs
+++ b/src/Configuration/DotNetConfigProvider.cs
@@ -6,7 +6,9 @@ namespace DotNetConfig
 {
     class DotNetConfigProvider : ConfigurationProvider
     {
-        Config configuration = Config.Build();
+        Config configuration;
+
+        public DotNetConfigProvider(string? path = null) => configuration = Config.Build(path);
 
         public override void Load()
         {
@@ -25,7 +27,8 @@ public override void Load()
 
                 key += ConfigurationPath.KeyDelimiter + entry.Variable;
 
-                data[key] = string.IsNullOrWhiteSpace(entry.RawValue) ? "true" : entry.RawValue!.Trim('"');
+                if (!data.ContainsKey(key))
+                    data[key] = string.IsNullOrWhiteSpace(entry.RawValue) ? "true" : entry.RawValue!.Trim('"');
             }
 
             Data = data;
diff --git a/src/Configuration/DotNetConfigSource.cs b/src/Configuration/DotNetConfigSource.cs
index d5a9ba7..c9de4e5 100644
--- a/src/Configuration/DotNetConfigSource.cs
+++ b/src/Configuration/DotNetConfigSource.cs
@@ -4,6 +4,10 @@ namespace DotNetConfig
 {
     class DotNetConfigSource : IConfigurationSource
     {
-        public IConfigurationProvider Build(IConfigurationBuilder builder) => new DotNetConfigProvider();
+        readonly string? path;
+
+        public DotNetConfigSource(string? path = null) => this.path = path;
+
+        public IConfigurationProvider Build(IConfigurationBuilder builder) => new DotNetConfigProvider(path);
     }
 }