diff --git a/src/Java.Interop.Tools.TypeNameMappings/Java.Interop.Tools.TypeNameMappings/JavaNativeTypeManager.cs b/src/Java.Interop.Tools.TypeNameMappings/Java.Interop.Tools.TypeNameMappings/JavaNativeTypeManager.cs
index 9d81e3804..17e895720 100644
--- a/src/Java.Interop.Tools.TypeNameMappings/Java.Interop.Tools.TypeNameMappings/JavaNativeTypeManager.cs
+++ b/src/Java.Interop.Tools.TypeNameMappings/Java.Interop.Tools.TypeNameMappings/JavaNativeTypeManager.cs
@@ -196,9 +196,9 @@ public static string ToJniName (Type type)
 		// Trimming warnings are not enabled for netstandard2.0 in this project.
 		static bool ShouldCheckSpecialExportJniType (Type type) =>
 #if NETSTANDARD2_0
-			type.GetInterfaces ().Any (t => t.FullName == "Java.Interop.IJavaPeerable");
+			!type.GetInterfaces ().Any (t => t.FullName == "Java.Interop.IJavaPeerable");
 #else
-			IJavaPeerableType.Value.IsAssignableFrom (type);
+			!IJavaPeerableType.Value.IsAssignableFrom (type);
 #endif
 
 		public static string ToJniName (string jniType, int rank)
diff --git a/tests/Java.Interop.Tools.JavaCallableWrappers-Tests/Java.Interop.Tools.JavaCallableWrappers/JavaNativeTypeManagerTests.cs b/tests/Java.Interop.Tools.JavaCallableWrappers-Tests/Java.Interop.Tools.JavaCallableWrappers/JavaNativeTypeManagerTests.cs
index a86ff05f3..2c8e7b920 100644
--- a/tests/Java.Interop.Tools.JavaCallableWrappers-Tests/Java.Interop.Tools.JavaCallableWrappers/JavaNativeTypeManagerTests.cs
+++ b/tests/Java.Interop.Tools.JavaCallableWrappers-Tests/Java.Interop.Tools.JavaCallableWrappers/JavaNativeTypeManagerTests.cs
@@ -55,5 +55,14 @@ public void LowercaseWithAssemblyName ()
 			Assert.AreEqual ("assembly_mscorlib.system", JavaNativeTypeManager.GetPackageName (typeof (string)));
 #endif  // !NET
 		}
+
+		[Test]
+		[TestCase (typeof (string), "java/lang/String")]
+		[TestCase (typeof (Type),   "java/lang/Object")]
+		public void ToJniName (Type type, string expected)
+		{
+			string actual = JavaNativeTypeManager.ToJniName (type);
+			Assert.AreEqual (expected, actual);
+		}
 	}
 }