diff --git a/eng/testing/tests.ioslike.targets b/eng/testing/tests.ioslike.targets
index 24de43e2a24225..c1ea8a9e5e82aa 100644
--- a/eng/testing/tests.ioslike.targets
+++ b/eng/testing/tests.ioslike.targets
@@ -13,6 +13,7 @@
     <NativeLib>Static</NativeLib>
     <CustomNativeMain>true</CustomNativeMain>
     <_SuppressNativeLibEventSourceWarning>true</_SuppressNativeLibEventSourceWarning>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
   </PropertyGroup>
 
   <ItemGroup Condition="'$(UseNativeAOTRuntime)' == 'true' and '$(IncludesTestRunner)' != 'false' and '$(TargetFrameworkIdentifier)' == '.NETCoreApp'">
diff --git a/src/libraries/Common/tests/AppleTestRunner/AppleTestRunner.cs b/src/libraries/Common/tests/AppleTestRunner/AppleTestRunner.cs
index 2af27adacbe6d0..ef38eea9823e21 100644
--- a/src/libraries/Common/tests/AppleTestRunner/AppleTestRunner.cs
+++ b/src/libraries/Common/tests/AppleTestRunner/AppleTestRunner.cs
@@ -17,14 +17,14 @@
 using Microsoft.DotNet.XHarness.TestRunners.Common;
 using Microsoft.DotNet.XHarness.TestRunners.Xunit;
 
-public class SimpleTestRunner : iOSApplicationEntryPoint, IDevice
+public partial class SimpleTestRunner : iOSApplicationEntryPoint, IDevice
 {
     // to be wired once https://github.com/dotnet/xharness/pull/46 is merged
-    [DllImport("__Internal")]
-    public extern static void mono_ios_append_output (string value);
+    [LibraryImport("__Internal", EntryPoint = "mono_ios_append_output", StringMarshalling = StringMarshalling.Utf8)]
+    private static partial void mono_ios_append_output (string value);
 
-    [DllImport("__Internal")]
-    public extern static void mono_ios_set_summary (string value);
+    [LibraryImport("__Internal", EntryPoint = "mono_ios_set_summary", StringMarshalling = StringMarshalling.Utf8)]
+    private static partial void mono_ios_set_summary (string value);
 
     private static List<string> s_testLibs = new List<string>();
     private static List<Assembly>? s_testAssemblies;
diff --git a/src/libraries/Common/tests/AppleTestRunner/AppleTestRunner.csproj b/src/libraries/Common/tests/AppleTestRunner/AppleTestRunner.csproj
index 4f33bc8b4a5655..c993673026325a 100644
--- a/src/libraries/Common/tests/AppleTestRunner/AppleTestRunner.csproj
+++ b/src/libraries/Common/tests/AppleTestRunner/AppleTestRunner.csproj
@@ -2,6 +2,7 @@
   <PropertyGroup>
     <OutputType>Exe</OutputType>
     <Nullable>enable</Nullable>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <TargetFramework>$(NetCoreAppCurrent)</TargetFramework>
   </PropertyGroup>
   <ItemGroup>