diff --git a/IDEHelper/Compiler/BfExprEvaluator.cpp b/IDEHelper/Compiler/BfExprEvaluator.cpp
index 993ac044..8fcd5718 100644
--- a/IDEHelper/Compiler/BfExprEvaluator.cpp
+++ b/IDEHelper/Compiler/BfExprEvaluator.cpp
@@ -18145,6 +18145,18 @@ void BfExprEvaluator::DoInvocation(BfAstNode* target, BfMethodBoundExpression* m
 				expectingType = underlyingType;
 			}
 
+			BfType* inRefType = NULL;
+			if ((expectingType != NULL) && (expectingType->IsRef()))
+			{
+				auto refType = (BfRefType*)expectingType;
+				if (refType->mRefKind == BfRefType::RefKind_In)
+				{
+					inRefType = expectingType;
+					auto underlyingType = expectingType->GetUnderlyingType();
+					expectingType = underlyingType;
+				}
+			}
+
 			if (expectingType != NULL)
 			{
 				if (expectingType->IsSizedArray())
@@ -18188,6 +18200,12 @@ void BfExprEvaluator::DoInvocation(BfAstNode* target, BfMethodBoundExpression* m
 								mResult = ctorResult;
 							mModule->ValidateAllocation(expectingType, invocationExpr->mTarget);
 
+							if ((inRefType != NULL) && (mResult.mType == expectingType) && (mResult.IsAddr()))
+							{
+								// Put back the 'in'
+								mResult = BfTypedValue(mResult.mValue, inRefType);
+							}
+
 							return;
 						}
 					}
diff --git a/IDEHelper/Tests/src/MethodCalls.bf b/IDEHelper/Tests/src/MethodCalls.bf
index e48e3886..bd80fdb0 100644
--- a/IDEHelper/Tests/src/MethodCalls.bf
+++ b/IDEHelper/Tests/src/MethodCalls.bf
@@ -126,6 +126,11 @@ namespace Tests
 		{
 		}
 
+		public static int InCallStruct(in StructA val)
+		{
+			return val.mA + val.mB;
+		}
+
 		public static int ParamsA(int a, params Span<int> ints)
 		{
 			int result = a;
@@ -207,6 +212,9 @@ namespace Tests
 			StructA sa2 = .(200, 201);
 			StructA sa3 = .(300, 301);
 
+			Test.Assert(InCallStruct(sa) == 201);
+			Test.Assert(InCallStruct(.(200, 202)) == 402);
+
 			Test.Assert(Method0(sa) == 100);
 			Test.Assert(Method1(sa, sa2) == 200);
 			Test.Assert(Method2(sa, sa2, sa3) == 300);