diff --git a/src/Microsoft.Azure.NotificationHubs/Auth/SharedAccessSignatureBuilder.cs b/src/Microsoft.Azure.NotificationHubs/Auth/SharedAccessSignatureBuilder.cs
index 6fb1d64..388a53a 100644
--- a/src/Microsoft.Azure.NotificationHubs/Auth/SharedAccessSignatureBuilder.cs
+++ b/src/Microsoft.Azure.NotificationHubs/Auth/SharedAccessSignatureBuilder.cs
@@ -32,7 +32,7 @@ public static string BuildSignature(
             // Normalize the target URI to use the SB scheme.
 
             string expiresOn = BuildExpiresOn(timeToLive);
-            string audienceUri = UrlEncode(targetUri);
+            string audienceUri = UrlEncode(targetUri.ToLowerInvariant());
             List<string> fields = new List<string>();
             fields.Add(audienceUri);
             fields.Add(expiresOn);
@@ -57,9 +57,9 @@ public static string BuildSignature(
         internal static string UrlEncode(string url)
         {
 #if NET461
-            return System.Net.WebUtility.UrlEncode(url.ToLowerInvariant());
+            return System.Net.WebUtility.UrlEncode(url);
 #else
-            return HttpUtility.UrlEncode(url.ToLowerInvariant());
+            return HttpUtility.UrlEncode(url);
 #endif
         }
 
diff --git a/src/Microsoft.Azure.NotificationHubs/Microsoft.Azure.NotificationHubs.csproj b/src/Microsoft.Azure.NotificationHubs/Microsoft.Azure.NotificationHubs.csproj
index 0d7087a..95f1bc1 100644
--- a/src/Microsoft.Azure.NotificationHubs/Microsoft.Azure.NotificationHubs.csproj
+++ b/src/Microsoft.Azure.NotificationHubs/Microsoft.Azure.NotificationHubs.csproj
@@ -7,7 +7,7 @@
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <VersionPrefix>4.0.0.0</VersionPrefix>
     <PackageId>Microsoft.Azure.NotificationHubs</PackageId>
-    <PackageVersion>4.0.0-preview1</PackageVersion>
+    <PackageVersion>4.0.0-preview2</PackageVersion>
     <Authors>Microsoft</Authors>
     <PackageLicenseUrl>http://go.microsoft.com/fwlink/?LinkId=218949</PackageLicenseUrl>
     <PackageProjectUrl>https://aka.ms/NHNuget</PackageProjectUrl>