diff --git a/docs/release-notes/.FSharp.Compiler.Service/11.0.100.md b/docs/release-notes/.FSharp.Compiler.Service/11.0.100.md
index 221cb6bde01..4c284c5ab0d 100644
--- a/docs/release-notes/.FSharp.Compiler.Service/11.0.100.md
+++ b/docs/release-notes/.FSharp.Compiler.Service/11.0.100.md
@@ -51,6 +51,7 @@
 * Fix internal error when using custom attribute with `[<Optional>]` value type parameter and no `[<DefaultParameterValue>]`. ([Issue #8353](https://github.com/dotnet/fsharp/issues/8353), [PR #19484](https://github.com/dotnet/fsharp/pull/19484))
 * Fix parallel compilation of scripts ([PR #19649](https://github.com/dotnet/fsharp/pull/19649))
 * Parser: fix unexpected diagnostics in debug builds, improve error messages ([PR #19730](https://github.com/dotnet/fsharp/pull/19730))
+* Fix `[<Struct>] ?param` optional parameters could not be passed using the explicit `?param = expr` caller-side syntax with a `ValueOption` value. ([Issue #19711](https://github.com/dotnet/fsharp/issues/19711), [PR #19742](https://github.com/dotnet/fsharp/pull/19742))
 
 ### Added
 
diff --git a/src/Compiler/Checking/Expressions/CheckExpressions.fs b/src/Compiler/Checking/Expressions/CheckExpressions.fs
index 30d49e776c8..c3c416c4f13 100644
--- a/src/Compiler/Checking/Expressions/CheckExpressions.fs
+++ b/src/Compiler/Checking/Expressions/CheckExpressions.fs
@@ -10135,13 +10135,21 @@ and TcMethodApplication_SplitSynArguments
 
         | _ ->
             let unnamedCurriedCallerArgs = unnamedCurriedCallerArgs |> List.mapSquared MakeUnnamedCallerArgInfo
+            let supportsValueOptionalArgs =
+                g.langVersion.SupportsFeature LanguageFeature.SupportValueOptionsAsOptionalParameters
             let namedCurriedCallerArgs = namedCurriedCallerArgs |> List.mapSquared (fun (isOpt, nm, x) ->
                 let ty = GetNewInferenceTypeForMethodArg cenv x
                 // #435263: compiler crash with .net optional parameters and F# optional syntax
-                // named optional arguments should always have option type
-                // STRUCT OPTIONS: if we allow struct options as optional arguments then we should relax this and rely
-                // on later inference to work out if this is a struct option or ref option
-                let ty = if isOpt then mkOptionTy denv.g ty else ty
+                // For LangVersion < 10 named optional arguments are constrained to option type here
+                // so that an early, friendly error is reported. With LangVersion >= 10 the parameter
+                // may be a struct-option (voption) — see issue dotnet/fsharp#19711 — so we leave the
+                // type as a fresh inference variable and let later unification (CalleeSide branch in
+                // AdjustCalledArgTypeForOptionals) pick option<_> or voption<_>.
+                let ty =
+                    if isOpt && not supportsValueOptionalArgs then
+                        mkOptionTy denv.g ty
+                    else
+                        ty
                 nm, isOpt, x, ty, x.Range)
 
             (Some (unnamedCurriedCallerArgs, namedCurriedCallerArgs), None, exprTy)
diff --git a/tests/FSharp.Compiler.ComponentTests/Conformance/BasicGrammarElements/MemberDefinitions/OptionalArguments/OptionalArguments.fs b/tests/FSharp.Compiler.ComponentTests/Conformance/BasicGrammarElements/MemberDefinitions/OptionalArguments/OptionalArguments.fs
index 48b27ecb666..0af170a336a 100644
--- a/tests/FSharp.Compiler.ComponentTests/Conformance/BasicGrammarElements/MemberDefinitions/OptionalArguments/OptionalArguments.fs
+++ b/tests/FSharp.Compiler.ComponentTests/Conformance/BasicGrammarElements/MemberDefinitions/OptionalArguments/OptionalArguments.fs
@@ -634,4 +634,81 @@ let main _args =
         |> ILVerifierModule.verifyPEFileWithSystemDlls
         |> run
         |> verifyOutputContains [|"main;18;hello;42;"|]
-    
\ No newline at end of file
+    
+    // Regression test for https://github.com/dotnet/fsharp/issues/19711
+    // `?name = expr` (explicit caller-side question-mark syntax) must accept a
+    // ValueOption when the declared parameter is `[<Struct>] ?name`.
+    [<Fact>]
+    let ``ValueOption optional parameters can be passed using ?param syntax on methods`` () =
+        FSharp """
+module Program
+type OptionalArguments() =
+    member _.NoProblem (?number : int32) =
+        match number with
+        | Some v -> printfn "RSome %d" v
+        | None -> printfn "RNone"
+    member _.Problem ([<Struct>] ?number : int32) =
+        match number with
+        | ValueSome v -> printfn "VSome %d" v
+        | ValueNone -> printfn "VNone"
+
+[<EntryPoint>]
+let main _ =
+    let o = OptionalArguments()
+    o.NoProblem 123
+    o.NoProblem (number = 123)
+    o.NoProblem (?number = None)
+    o.NoProblem (?number = Some 123)
+    o.NoProblem (?number = Unchecked.defaultof<_>)
+    o.Problem 123
+    o.Problem (number = 123)
+    o.Problem (?number = ValueNone)
+    o.Problem (?number = ValueSome 123)
+    o.Problem (?number = Unchecked.defaultof<_>)
+    0
+        """
+        |> asExe
+        |> withOptions ["--nowarn:988"]
+        |> compileAndRun
+        |> shouldSucceed
+        |> withOutputContainsAllInOrder [
+            "RSome 123"; "RSome 123"; "RNone"; "RSome 123"; "RNone"
+            "VSome 123"; "VSome 123"; "VNone"; "VSome 123"; "VNone"
+        ]
+
+    [<Fact>]
+    let ``ValueOption optional parameters can be passed using ?param syntax on constructors`` () =
+        FSharp """
+module Program
+type X<'T>([<Struct>] ?x : 'T) =
+    member _.M() =
+        match x with
+        | ValueSome v -> printfn "VSome %A" v
+        | ValueNone -> printfn "VNone"
+
+[<EntryPoint>]
+let main _ =
+    X<int>(?x = ValueSome 1).M()
+    X<int>(?x = ValueNone).M()
+    X<int>(?x = Unchecked.defaultof<_>).M()
+    0
+        """
+        |> asExe
+        |> withOptions ["--nowarn:988"]
+        |> compileAndRun
+        |> shouldSucceed
+        |> withOutputContainsAllInOrder ["VSome 1"; "VNone"; "VNone"]
+
+    [<Fact>]
+    let ``ValueOption optional parameters via ?param syntax fail with langversion 9`` () =
+        FSharp """
+module Program
+type X() =
+    static member M ([<Struct>] ?x : int) = ()
+
+X.M(?x = ValueSome 1)
+        """
+        |> withLangVersion90
+        |> typecheck
+        |> shouldFail
+        |> withDiagnosticMessageMatches "voption"