diff --git a/ICSharpCode.Decompiler.Tests/ICSharpCode.Decompiler.Tests.csproj b/ICSharpCode.Decompiler.Tests/ICSharpCode.Decompiler.Tests.csproj
index 2851e3eea..d7153d8bb 100644
--- a/ICSharpCode.Decompiler.Tests/ICSharpCode.Decompiler.Tests.csproj
+++ b/ICSharpCode.Decompiler.Tests/ICSharpCode.Decompiler.Tests.csproj
@@ -252,6 +252,7 @@
     <Compile Include="TestCases\Pretty\ConstantsTests.cs" />
     <Compile Include="TestCases\Pretty\CS73_StackAllocInitializers.cs" />
     <Compile Include="TestCases\Pretty\OptionalArguments.cs" />
+    <Compile Include="TestCases\Pretty\OptionalArgumentsDisabled.cs" />
     <Compile Include="TestCases\Pretty\CustomShortCircuitOperators.cs" />
     <Compile Include="TestCases\Pretty\ReduceNesting.cs" />
     <Compile Include="TestCases\Pretty\InterfaceTests.cs" />
diff --git a/ICSharpCode.Decompiler.Tests/PrettyTestRunner.cs b/ICSharpCode.Decompiler.Tests/PrettyTestRunner.cs
index d28edc76a..f34b96b5b 100644
--- a/ICSharpCode.Decompiler.Tests/PrettyTestRunner.cs
+++ b/ICSharpCode.Decompiler.Tests/PrettyTestRunner.cs
@@ -599,6 +599,17 @@ namespace ICSharpCode.Decompiler.Tests
 			await RunForLibrary(cscOptions: cscOptions);
 		}
 
+		[Test]
+		public async Task OptionalArgumentsDisabled([ValueSource(nameof(defaultOptions))] CompilerOptions cscOptions)
+		{
+			await RunForLibrary(
+				cscOptions: cscOptions,
+				configureDecompiler: settings => {
+					settings.OptionalArguments = false;
+				}
+			);
+		}
+
 		[Test]
 		public async Task Comparisons([ValueSource(nameof(defaultOptions))] CompilerOptions cscOptions)
 		{
diff --git a/ICSharpCode.Decompiler.Tests/TestCases/Pretty/OptionalArgumentsDisabled.cs b/ICSharpCode.Decompiler.Tests/TestCases/Pretty/OptionalArgumentsDisabled.cs
new file mode 100644
index 000000000..b33456f2c
--- /dev/null
+++ b/ICSharpCode.Decompiler.Tests/TestCases/Pretty/OptionalArgumentsDisabled.cs
@@ -0,0 +1,19 @@
+namespace ICSharpCode.Decompiler.Tests.TestCases.Pretty
+{
+	public class OptionalArgumentsDisabled
+	{
+		public void Test()
+		{
+			MixedArguments("123", 0, 0);
+			OnlyOptionalArguments(0, 0);
+		}
+
+		public void MixedArguments(string msg, int a = 0, int b = 0)
+		{
+		}
+
+		public void OnlyOptionalArguments(int a = 0, int b = 0)
+		{
+		}
+	}
+}
diff --git a/ICSharpCode.Decompiler/CSharp/CallBuilder.cs b/ICSharpCode.Decompiler/CSharp/CallBuilder.cs
index f4fa1fb03..e1ee32c3b 100644
--- a/ICSharpCode.Decompiler/CSharp/CallBuilder.cs
+++ b/ICSharpCode.Decompiler/CSharp/CallBuilder.cs
@@ -967,7 +967,8 @@ namespace ICSharpCode.Decompiler.CSharp
 				}
 				else
 				{
-					firstOptionalArgumentIndex = -2;
+					if (firstOptionalArgumentIndex != -1)
+						firstOptionalArgumentIndex = -2;
 				}
 				if (expressionBuilder.settings.ExpandParamsArguments && parameter.IsParams && i + 1 == callArguments.Count && argumentToParameterMap == null)
 				{