diff --git a/src/EditorFeatures/VisualBasicTest/Diagnostics/InsertMissingCast/InsertMissingCastTests.vb b/src/EditorFeatures/VisualBasicTest/Diagnostics/InsertMissingCast/InsertMissingCastTests.vb
index 9cc3d5f7f7d3a5644ed9f536efd19a25a3d1ecc2..137cc15cd848838d5f83d22853b741cd068c82c9 100644
--- a/src/EditorFeatures/VisualBasicTest/Diagnostics/InsertMissingCast/InsertMissingCastTests.vb
+++ b/src/EditorFeatures/VisualBasicTest/Diagnostics/InsertMissingCast/InsertMissingCastTests.vb
@@ -87,5 +87,12 @@ NewLines("Option Strict On \n Module Program \n Sub Main(args As String()) \n Di
             TestMissing(
 NewLines("Option Strict On \n Class A \n End Class \n Class B \n End Class \n Module Program[||] \n Sub Main(args As String()) \n Dim x As A = New B() \n End Sub \n End Module"))
         End Sub
+
+        <Fact(), Trait(Traits.Feature, Traits.Features.CodeActionsInsertMissingCast)>
+        Public Sub TestOptionStrictOn()
+            Test(
+NewLines("Option Strict On \n Module Module1 \n Sub Main() \n Dim red = ColorF.FromArgb(255, 255, 0, 0) \n Dim c As Color = [|red|] \n End Sub \n End Module \n Public Structure ColorF \n Public A, R, G, B As Single \n Public Shared Function FromArgb(a As Double, r As Double, g As Double, b As Double) As ColorF \n Return New ColorF With {.A = CSng(a), .R = CSng(r), .G = CSng(g), .B = CSng(b)} \n End Function \n Public Shared Widening Operator CType(x As Color) As ColorF \n Return ColorF.FromArgb(x.A / 255, x.R / 255, x.G / 255, x.B / 255) \n End Operator \n Public Shared Narrowing Operator CType(x As ColorF) As Color \n Return Color.FromArgb(CByte(x.A * 255), CByte(x.R * 255), CByte(x.G * 255), CByte(x.B * 255)) \n End Operator \n End Structure \n Public Structure Color \n Public A, R, G, B As Byte \n Public Shared Function FromArgb(a As Byte, r As Byte, g As Byte, b As Byte) As Color \n Return New Color With {.A = a, .R = r, .G = g, .B = b} \n End Function \n End Structure"),
+NewLines("Option Strict On \n Module Module1 \n Sub Main() \n Dim red = ColorF.FromArgb(255, 255, 0, 0) \n Dim c As Color = CType(red, Color) \n End Sub \n End Module \n Public Structure ColorF \n Public A, R, G, B As Single \n Public Shared Function FromArgb(a As Double, r As Double, g As Double, b As Double) As ColorF \n Return New ColorF With {.A = CSng(a), .R = CSng(r), .G = CSng(g), .B = CSng(b)} \n End Function \n Public Shared Widening Operator CType(x As Color) As ColorF \n Return ColorF.FromArgb(x.A / 255, x.R / 255, x.G / 255, x.B / 255) \n End Operator \n Public Shared Narrowing Operator CType(x As ColorF) As Color \n Return Color.FromArgb(CByte(x.A * 255), CByte(x.R * 255), CByte(x.G * 255), CByte(x.B * 255)) \n End Operator \n End Structure \n Public Structure Color \n Public A, R, G, B As Byte \n Public Shared Function FromArgb(a As Byte, r As Byte, g As Byte, b As Byte) As Color \n Return New Color With {.A = a, .R = r, .G = g, .B = b} \n End Function \n End Structure"))
+        End Sub
     End Class
 End Namespace
diff --git a/src/EditorFeatures/VisualBasicTest/Diagnostics/RemoveUnnecessaryCast/RemoveUnnecessaryCastTests.vb b/src/EditorFeatures/VisualBasicTest/Diagnostics/RemoveUnnecessaryCast/RemoveUnnecessaryCastTests.vb
index fe788a93de4fca458aab80e52557d60623a263ae..a89d717acf431e64492f201c20566eee82061018 100644
--- a/src/EditorFeatures/VisualBasicTest/Diagnostics/RemoveUnnecessaryCast/RemoveUnnecessaryCastTests.vb
+++ b/src/EditorFeatures/VisualBasicTest/Diagnostics/RemoveUnnecessaryCast/RemoveUnnecessaryCastTests.vb
@@ -2363,7 +2363,7 @@ End Class
         <WorkItem(544655)>
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)>
         Public Sub RemoveCastToICloneableForDelegate()
-            ' Note: The cast below can be removed because delegates are implictly sealed.
+            ' Note: The cast below can be removed because delegates are implicitly sealed.
 
             Dim markup =
 <File>
@@ -2396,7 +2396,7 @@ End Class
         <WorkItem(545926)>
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)>
         Public Sub RemoveCastToICloneableForArray()
-            ' Note: The cast below can be removed because arrays are implictly sealed.
+            ' Note: The cast below can be removed because arrays are implicitly sealed.
 
             Dim markup =
 <File>
@@ -2427,7 +2427,7 @@ End Class
         <WorkItem(529937)>
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)>
         Public Sub RemoveCastToICloneableForArray2()
-            ' Note: The cast below can be removed because arrays are implictly sealed.
+            ' Note: The cast below can be removed because arrays are implicitly sealed.
 
             Dim markup =
 <File>
@@ -2456,7 +2456,7 @@ End Module
         <WorkItem(529897)>
         <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)>
         Public Sub RemoveCastToIConvertibleForEnum()
-            ' Note: The cast below can be removed because enums are implictly sealed.
+            ' Note: The cast below can be removed because enums are implicitly sealed.
 
             Dim markup =
 <File>
@@ -2691,6 +2691,84 @@ Class Program
         End If
     End Sub
 End Class
+</File>
+            TestMissing(markup)
+        End Sub
+
+        <WorkItem(3163, "https://github.com/dotnet/roslyn/issues/3163")>
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)>
+        Public Sub DoNotRemoveCastInUserDefinedNarrowingConverionStrictOn()
+            Dim markup =
+<File>
+Option Strict On
+
+Module Module1
+
+    Sub Main()
+        Dim red = ColorF.FromArgb(255, 255, 0, 0)
+        Dim c As Color = [|CType(red, Color)|]
+    End Sub
+
+End Module
+
+Public Structure ColorF
+    Public A, R, G, B As Single
+    Public Shared Function FromArgb(a As Double, r As Double, g As Double, b As Double) As ColorF
+        Return New ColorF With {.A = CSng(a), .R = CSng(r), .G = CSng(g), .B = CSng(b)}
+    End Function
+    Public Shared Widening Operator CType(x As Color) As ColorF
+        Return ColorF.FromArgb(x.A / 255, x.R / 255, x.G / 255, x.B / 255)
+    End Operator
+    Public Shared Narrowing Operator CType(x As ColorF) As Color
+        Return Color.FromArgb(CByte(x.A * 255), CByte(x.R * 255), CByte(x.G * 255), CByte(x.B * 255))
+    End Operator
+End Structure
+
+Public Structure Color
+    Public A, R, G, B As Byte
+    Public Shared Function FromArgb(a As Byte, r As Byte, g As Byte, b As Byte) As Color
+        Return New Color With {.A = a, .R = r, .G = g, .B = b}
+    End Function
+End Structure
+</File>
+            TestMissing(markup)
+        End Sub
+
+        <WorkItem(3163, "https://github.com/dotnet/roslyn/issues/3163")>
+        <Fact, Trait(Traits.Feature, Traits.Features.CodeActionsRemoveUnnecessaryCast)>
+        Public Sub DoNotRemoveCastInUserDefinedNarrowingConverionStrictOff()
+            Dim markup =
+<File>
+Option Strict Off
+
+Module Module1
+
+    Sub Main()
+        Dim red = ColorF.FromArgb(255, 255, 0, 0)
+        Dim c As Color = [|CType(red, Color)|]
+    End Sub
+
+End Module
+
+Public Structure ColorF
+    Public A, R, G, B As Single
+    Public Shared Function FromArgb(a As Double, r As Double, g As Double, b As Double) As ColorF
+        Return New ColorF With {.A = CSng(a), .R = CSng(r), .G = CSng(g), .B = CSng(b)}
+    End Function
+    Public Shared Widening Operator CType(x As Color) As ColorF
+        Return ColorF.FromArgb(x.A / 255, x.R / 255, x.G / 255, x.B / 255)
+    End Operator
+    Public Shared Narrowing Operator CType(x As ColorF) As Color
+        Return Color.FromArgb(CByte(x.A * 255), CByte(x.R * 255), CByte(x.G * 255), CByte(x.B * 255))
+    End Operator
+End Structure
+
+Public Structure Color
+    Public A, R, G, B As Byte
+    Public Shared Function FromArgb(a As Byte, r As Byte, g As Byte, b As Byte) As Color
+        Return New Color With {.A = a, .R = r, .G = g, .B = b}
+    End Function
+End Structure
 </File>
             TestMissing(markup)
         End Sub
diff --git a/src/Features/VisualBasic/CodeFixes/InsertMissingCast/InsertMissingCastCodeFixProvider.vb b/src/Features/VisualBasic/CodeFixes/InsertMissingCast/InsertMissingCastCodeFixProvider.vb
index 0804811bccbad4509bb6892ddee42e7e9ca76b1e..df0bad79f94a9256f8dc9e0dd72e1c441eb1c201 100644
--- a/src/Features/VisualBasic/CodeFixes/InsertMissingCast/InsertMissingCastCodeFixProvider.vb
+++ b/src/Features/VisualBasic/CodeFixes/InsertMissingCast/InsertMissingCastCodeFixProvider.vb
@@ -12,10 +12,11 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.CodeFixes.InsertMissingCast
         Inherits CodeFixProvider
 
         Friend Const BC30512 As String = "BC30512" ' Option Strict On disallows implicit conversions from '{0}' to '{1}'.
+        Friend Const BC42016 As String = "BC42016" ' Implicit conversions from '{0}' to '{1}'.
 
         Public NotOverridable Overrides ReadOnly Property FixableDiagnosticIds As ImmutableArray(Of String)
             Get
-                Return ImmutableArray.Create(BC30512)
+                Return ImmutableArray.Create(BC30512, BC42016)
             End Get
         End Property
 
diff --git a/src/Workspaces/VisualBasic/Portable/Extensions/CastAnalyzer.vb b/src/Workspaces/VisualBasic/Portable/Extensions/CastAnalyzer.vb
index b6edbc3c8b655394d880af48797434f8c6c579f5..82660eb29b180caff5bbf15a985d7ae2c5ba2703 100644
--- a/src/Workspaces/VisualBasic/Portable/Extensions/CastAnalyzer.vb
+++ b/src/Workspaces/VisualBasic/Portable/Extensions/CastAnalyzer.vb
@@ -253,7 +253,8 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Extensions
                 If castToOuterType.IsUserDefined OrElse expressionToCastType.IsUserDefined Then
                     Return (HaveSameUserDefinedConversion(expressionToCastType, expressionToOuterType) OrElse
                             HaveSameUserDefinedConversion(castToOuterType, expressionToOuterType)) AndAlso
-                           UserDefinedConversionIsAllowed(_castNode, _semanticModel)
+                           (UserDefinedConversionIsAllowed(_castNode, _semanticModel) AndAlso
+                            Not expressionToCastType.IsNarrowing)
                 ElseIf expressionToOuterType.IsUserDefined Then
                     Return False
                 End If