diff --git a/BuildNotifications.Core.Tests/BuildNotifications.Core.Tests.csproj b/BuildNotifications.Core.Tests/BuildNotifications.Core.Tests.csproj
index 418efcd7..e7cda0a7 100644
--- a/BuildNotifications.Core.Tests/BuildNotifications.Core.Tests.csproj
+++ b/BuildNotifications.Core.Tests/BuildNotifications.Core.Tests.csproj
@@ -20,7 +20,7 @@
 			<PrivateAssets>all</PrivateAssets>
 		</PackageReference>
 		<PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.2.0"/>
-		<PackageReference Include="NSubstitute" Version="4.3.0"/>
+		<PackageReference Include="NSubstitute" Version="4.4.0"/>
 		<PackageReference Include="NSubstitute.Analyzers.CSharp" Version="1.0.15">
 			<PrivateAssets>all</PrivateAssets>
 			<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
diff --git a/BuildNotifications.Tests/BuildNotifications.Tests.csproj b/BuildNotifications.Tests/BuildNotifications.Tests.csproj
index 6e3fe823..9fad3ce5 100644
--- a/BuildNotifications.Tests/BuildNotifications.Tests.csproj
+++ b/BuildNotifications.Tests/BuildNotifications.Tests.csproj
@@ -27,7 +27,7 @@
 			<PrivateAssets>all</PrivateAssets>
 			<IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
 		</PackageReference>
-		<PackageReference Include="NSubstitute" Version="4.3.0"/>
+		<PackageReference Include="NSubstitute" Version="4.4.0"/>
 		<PackageReference Include="xunit" Version="2.4.1"/>
 		<PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
 			<PrivateAssets>all</PrivateAssets>