diff --git a/runtime/bindings-generator.cs b/runtime/bindings-generator.cs
index aecccea761..11851709de 100644
--- a/runtime/bindings-generator.cs
+++ b/runtime/bindings-generator.cs
@@ -1499,6 +1499,30 @@ namespace Xamarin.BindingMethods.Generator
 				}
 			);
 
+			data.Add (
+				new FunctionData {
+					Comment = " // void func (Quaternion, double)",
+					Prefix = "simd__",
+					Variants = Variants.NonStret,
+					Parameters = new ParameterData [] {
+						new ParameterData { TypeData = Types.QuatF },
+						new ParameterData { TypeData = Types.Double },
+					},
+				}
+			);
+
+			data.Add (
+				new FunctionData {
+					Comment = " // void func (Quaterniond, double)",
+					Prefix = "simd__",
+					Variants = Variants.NonStret,
+					Parameters = new ParameterData [] {
+						new ParameterData { TypeData = Types.QuatD },
+						new ParameterData { TypeData = Types.Double },
+					},
+				}
+			);
+
 			data.Add (
 				new FunctionData {
 					Comment = " // void func (Quaternion)",
@@ -1522,6 +1546,18 @@ namespace Xamarin.BindingMethods.Generator
 				}
 			);
 
+			data.Add (
+				new FunctionData {
+					Comment = " // Quaternion func (double)",
+					Prefix = "simd__",
+					Variants = Variants.All,
+					ReturnType = Types.QuatF,
+					Parameters = new ParameterData [] {
+						new ParameterData { TypeData = Types.Double },
+					},
+				}
+			);
+
 			// Required for ModelIO
 			data.Add (
 				new FunctionData {
diff --git a/src/modelio.cs b/src/modelio.cs
index bc43fa0001..249ab4407d 100644
--- a/src/modelio.cs
+++ b/src/modelio.cs
@@ -3047,12 +3047,15 @@ namespace ModelIO {
 	[iOS (13,0), Mac (10,15), TV (13,0)]
 	[BaseType (typeof (MDLAnimatedValue))]
 	interface MDLAnimatedQuaternion {
+		[MarshalDirective (NativePrefix = "xamarin_simd__", Library = "__Internal")]
 		[Export ("setFloatQuaternion:atTime:")]
 		void SetQuaternion (Quaternion value, double atTime);
 
+		[MarshalDirective (NativePrefix = "xamarin_simd__", Library = "__Internal")]
 		[Export ("setDoubleQuaternion:atTime:")]
 		void SetQuaternion (Quaterniond value, double atTime);
 
+		[MarshalDirective (NativePrefix = "xamarin_simd__", Library = "__Internal")]
 		[Export ("floatQuaternionAtTime:")]
 		Quaternion GetFloatQuaternion (double atTime);
 
diff --git a/tests/monotouch-test/ModelIO/MDLAnimatedValueTypesTests.cs b/tests/monotouch-test/ModelIO/MDLAnimatedValueTypesTests.cs
index 2169a76314..e552387b69 100644
--- a/tests/monotouch-test/ModelIO/MDLAnimatedValueTypesTests.cs
+++ b/tests/monotouch-test/ModelIO/MDLAnimatedValueTypesTests.cs
@@ -485,8 +485,9 @@ namespace MonoTouchFixtures.ModelIO {
 				var quat = new Quaternion (1.1f, 2.2f, 3.3f, 4.4f);
 
 				animatedQuat.SetQuaternion (quat, 0);
-				Asserts.AreEqual (quat, animatedQuat.GetFloatQuaternion (0), "A");
-				
+				var returnedQuat = animatedQuat.GetFloatQuaternion (0);
+				Asserts.AreEqual (quat, returnedQuat, "A");
+
 				animatedQuat.Reset (TestMatrices.QuaternionArray, TestMatrices.GetTimesArray (TestMatrices.QuaternionArray.Length));
 				var arr = animatedQuat.GetQuaternionValues (20);
 				Asserts.AreEqual (TestMatrices.QuaternionArray, arr, "C1");