diff --git a/GoCardless.Tests/FunctionalityTests.cs b/GoCardless.Tests/FunctionalityTests.cs
index 7ca26ab..302280a 100644
--- a/GoCardless.Tests/FunctionalityTests.cs
+++ b/GoCardless.Tests/FunctionalityTests.cs
@@ -172,6 +172,14 @@ public async Task RequestRetriesWithCustomValues(int numberOfFailures, bool shou
 
         }
 
-
+        [Test]
+        public async Task BooleansAreDowncasedInQueryString()
+        {
+            var responseFixture = "fixtures/mock_response.json";
+            http.EnqueueResponse(200, responseFixture);
+            var listRequest = new CustomerBankAccountListRequest(){ Enabled = true };
+            var listResponse = await client.CustomerBankAccounts.ListAsync(listRequest);
+            http.AssertRequestMade("GET", "/customer_bank_accounts?enabled=true");
+        }
     }
 }
diff --git a/GoCardless.Tests/GoCardless.Tests.csproj b/GoCardless.Tests/GoCardless.Tests.csproj
index ac96de5..242c228 100644
--- a/GoCardless.Tests/GoCardless.Tests.csproj
+++ b/GoCardless.Tests/GoCardless.Tests.csproj
@@ -92,6 +92,9 @@
     <None Update="fixtures\unused\validation_failed.json">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </None>
+    <None Update="fixtures\mock_response.json">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
   </ItemGroup>
 
 </Project>
\ No newline at end of file
diff --git a/GoCardless.Tests/fixtures/mock_response.json b/GoCardless.Tests/fixtures/mock_response.json
new file mode 100644
index 0000000..e97696e
--- /dev/null
+++ b/GoCardless.Tests/fixtures/mock_response.json
@@ -0,0 +1,9 @@
+{
+    "foo": {
+        "direct": "debit",
+        "amount": 1,
+        "dotnet": true,
+        "request_id": "abc-123",
+        "code": 200
+    }
+}
diff --git a/GoCardless/GoCardless.csproj b/GoCardless/GoCardless.csproj
index 1b13295..564c47e 100644
--- a/GoCardless/GoCardless.csproj
+++ b/GoCardless/GoCardless.csproj
@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <PackageId>GoCardless</PackageId>
-    <PackageVersion>2.0.5</PackageVersion>
+    <PackageVersion>2.0.6</PackageVersion>
     <Authors>GoCardless Ltd</Authors>
     <Description>Client for the GoCardless API - a powerful, simple solution for the collection of recurring bank-to-bank payments</Description>
     <PackageRequireLicenseAcceptance>false</PackageRequireLicenseAcceptance>
@@ -11,7 +11,7 @@
     <Copyright>GoCardless Ltd</Copyright>
     <PackageTags>gocardless payments rest api direct debit</PackageTags>
     <PackageLicenseUrl>https://github.com/gocardless/gocardless-dotnet/blob/master/LICENSE.txt</PackageLicenseUrl>
-    <PackageReleaseNotes>https://github.com/gocardless/gocardless-dotnet/releases/tag/v2.0.5</PackageReleaseNotes>
+    <PackageReleaseNotes>https://github.com/gocardless/gocardless-dotnet/releases/tag/v2.0.6</PackageReleaseNotes>
     <TargetFrameworks>netcoreapp1.1;net452</TargetFrameworks>
     <GeneratePackageOnBuild>True</GeneratePackageOnBuild>
   </PropertyGroup>
diff --git a/GoCardless/GoCardlessClient.cs b/GoCardless/GoCardlessClient.cs
index c33054b..21bf3f2 100644
--- a/GoCardless/GoCardlessClient.cs
+++ b/GoCardless/GoCardlessClient.cs
@@ -213,9 +213,9 @@ private HttpRequestMessage BuildHttpRequestMessage<T>(string method, string path
             var httpMethod = new HttpMethod(method);
 
             var requestMessage = new HttpRequestMessage(httpMethod, new Uri(_baseUrl, path));
-            requestMessage.Headers.Add("User-Agent", "gocardless-dotnet/2.0.5");
+            requestMessage.Headers.Add("User-Agent", "gocardless-dotnet/2.0.6");
             requestMessage.Headers.Add("GoCardless-Version", "2015-07-06");
-            requestMessage.Headers.Add("GoCardless-Client-Version", "2.0.5");
+            requestMessage.Headers.Add("GoCardless-Client-Version", "2.0.6");
             requestMessage.Headers.Add("GoCardless-Client-Library", "gocardless-dotnet");
             requestMessage.Headers.Authorization =
                 new System.Net.Http.Headers.AuthenticationHeaderValue("Bearer", _accessToken);
@@ -266,6 +266,8 @@ class Helpers
         {
             internal static string Stringify(object value)
             {
+                if (value is bool)
+                    return value.ToString().ToLower();
                 if (value is DateTimeOffset)
                     return ((DateTimeOffset?) value).Value.ToString("o");
                 var typeInfo = value.GetType().GetTypeInfo();
diff --git a/README.md b/README.md
index 1be6427..623f4b9 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,7 @@ For full details of the GoCardless API, see the [API docs](https://developer.goc
 
 To install `GoCardless`, run the following command in the [Package Manager Console](https://docs.microsoft.com/en-us/nuget/tools/package-manager-console)
 
-`Install-Package GoCardless -Version 2.0.5`
+`Install-Package GoCardless -Version 2.0.6`
 
 
 ## Usage