diff --git a/src/NuGetGallery/Services/PackageDeprecationManagementService.cs b/src/NuGetGallery/Services/PackageDeprecationManagementService.cs
index c24a9c9456..53e2e9ec38 100644
--- a/src/NuGetGallery/Services/PackageDeprecationManagementService.cs
+++ b/src/NuGetGallery/Services/PackageDeprecationManagementService.cs
@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
@@ -148,7 +148,7 @@ public async Task<UpdateDeprecationError> UpdateDeprecation(
             foreach (var version in versions)
             {
                 var normalizedVersion = NuGetVersionFormatter.Normalize(version);
-                var package = packages.SingleOrDefault(v => v.NormalizedVersion == normalizedVersion);
+                var package = packages.SingleOrDefault(v => StringComparer.OrdinalIgnoreCase.Equals(v.NormalizedVersion, normalizedVersion));
                 if (package == null)
                 {
                     return new UpdateDeprecationError(
@@ -181,4 +181,4 @@ await _deprecationService.UpdateDeprecation(
             return null;
         }
     }
-}
\ No newline at end of file
+}
diff --git a/tests/NuGetGallery.Facts/Services/PackageDeprecationManagementServiceFacts.cs b/tests/NuGetGallery.Facts/Services/PackageDeprecationManagementServiceFacts.cs
index 20b424c8f7..4170717547 100644
--- a/tests/NuGetGallery.Facts/Services/PackageDeprecationManagementServiceFacts.cs
+++ b/tests/NuGetGallery.Facts/Services/PackageDeprecationManagementServiceFacts.cs
@@ -1,4 +1,4 @@
-// Copyright (c) .NET Foundation. All rights reserved.
+// Copyright (c) .NET Foundation. All rights reserved.
 // Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
 
 using System;
@@ -856,7 +856,7 @@ private async Task AssertSuccessful(
 
                 var package2 = new Package
                 {
-                    NormalizedVersion = "1.0.0",
+                    NormalizedVersion = "1.0.0-RC1",
                     PackageRegistration = registration
                 };
 
@@ -932,7 +932,7 @@ private async Task AssertSuccessful(
 
                 var service = GetService<PackageDeprecationManagementService>();
 
-                var packageNormalizedVersions = new[] { package.NormalizedVersion, package2.NormalizedVersion };
+                var packageNormalizedVersions = new[] { package.NormalizedVersion, package2.NormalizedVersion.ToLowerInvariant() };
 
                 // Act
                 var result = await InvokeUpdateDeprecation(
@@ -981,4 +981,4 @@ private static Task<UpdateDeprecationError> InvokeUpdateDeprecation(
             }
         }
     }
-}
\ No newline at end of file
+}