diff --git a/Sources/SwiftWin32/App and Environment/ApplicationMain.swift b/Sources/SwiftWin32/App and Environment/ApplicationMain.swift
index a63c6869..793b2bfe 100644
--- a/Sources/SwiftWin32/App and Environment/ApplicationMain.swift	
+++ b/Sources/SwiftWin32/App and Environment/ApplicationMain.swift	
@@ -216,8 +216,8 @@ public func ApplicationMain(_ argc: Int32,
     // to execute, we wait until a new message is placed in the thread's message
     // queue or the timer must fire, otherwise we proceed to the next iteration
     // of mainLoop, using 0 as the wait timeout.
-    _ = WaitMessage(DWORD(exactly: limitDate?.timeIntervalSinceNow ?? 0 * 1000)
-                        ?? DWORD.max)
+    _ = WaitMessage(UINT(exactly: limitDate?.timeIntervalSinceNow ?? 0 * 1000)
+                        ?? UINT.max)
   }
 
   Application.shared.delegate?.applicationWillTerminate(Application.shared)
diff --git a/Sources/SwiftWin32/Support/WinSDK+Extensions.swift b/Sources/SwiftWin32/Support/WinSDK+Extensions.swift
index e87d7ec3..4ee3def9 100644
--- a/Sources/SwiftWin32/Support/WinSDK+Extensions.swift
+++ b/Sources/SwiftWin32/Support/WinSDK+Extensions.swift
@@ -3,6 +3,18 @@
 
 import WinSDK
 
+#if arch(i386) || arch(arm)
+@_transparent
+internal func GetWindowLongPtrW(_ hWnd: HWND, _ nIndex: CInt) -> LONG {
+  return GetWindowLongW(hWnd, nIndex)
+}
+
+@_transparent
+internal func SetWindowLongPtrW(_ hWnd: HWND, _ nIndex: CInt, _ dwNewLong: LONG) -> LONG {
+  return SetWindowLongW(hWnd, nIndex, dwNewLong)
+}
+#endif
+
 internal let IDC_ARROW: UnsafePointer<WCHAR> =
     UnsafePointer<WCHAR>(bitPattern: 32512)!
 
@@ -11,52 +23,52 @@ internal let IDC_ARROW: UnsafePointer<WCHAR> =
 // winreg.h
 @_transparent
 internal var HKEY_CLASSES_ROOT: HKEY? {
-  HKEY(bitPattern: 0x80000000)
+  HKEY(bitPattern: UInt(0x80000000))
 }
 
 @_transparent
 internal var HKEY_CURRENT_USER: HKEY? {
-  HKEY(bitPattern: 0x80000001)
+  HKEY(bitPattern: UInt(0x80000001))
 }
 
 @_transparent
 internal var HKEY_LOCAL_MACHINE: HKEY? {
-  HKEY(bitPattern: 0x80000002)
+  HKEY(bitPattern: UInt(0x80000002))
 }
 
 @_transparent
 internal var HKEY_USERS: HKEY? {
-  HKEY(bitPattern: 0x80000003)
+  HKEY(bitPattern: UInt(0x80000003))
 }
 
 @_transparent
 internal var HKEY_PERFORMANCE_DATA: HKEY? {
-  HKEY(bitPattern: 0x80000004)
+  HKEY(bitPattern: UInt(0x80000004))
 }
 
 @_transparent
 internal var HKEY_PERFORMANCE_TEXT: HKEY? {
-  HKEY(bitPattern: 0x80000050)
+  HKEY(bitPattern: UInt(0x80000050))
 }
 
 @_transparent
 internal var HKEY_PERFORMANCE_NLSTEXT: HKEY? {
-  HKEY(bitPattern: 0x80000060)
+  HKEY(bitPattern: UInt(0x80000060))
 }
 
 @_transparent
 internal var HKEY_CURRENT_CONFIG: HKEY? {
-  HKEY(bitPattern: 0x80000005)
+  HKEY(bitPattern: UInt(0x80000005))
 }
 
 @_transparent
 internal var HKEY_DYN_DATA: HKEY? {
-  HKEY(bitPattern: 0x80000006)
+  HKEY(bitPattern: UInt(0x80000006))
 }
 
 @_transparent
 internal var HKEY_CURRENT_USER_LOCAL_SETTINGS: HKEY? {
-  HKEY(bitPattern: 0x80000007)
+  HKEY(bitPattern: UInt(0x80000007))
 }
 
 #endif
diff --git a/Sources/SwiftWin32/Text Display and Fonts/Font.swift b/Sources/SwiftWin32/Text Display and Fonts/Font.swift
index 3b505eaa..c661a79a 100644
--- a/Sources/SwiftWin32/Text Display and Fonts/Font.swift	
+++ b/Sources/SwiftWin32/Text Display and Fonts/Font.swift	
@@ -231,7 +231,7 @@ public class Font {
       log.error("GetObjectW: \(Error(win32: GetLastError()))")
       return self
     }
-    lfFont.lfHeight = PointToLogical(fontSize)
+    lfFont.lfHeight = LONG(PointToLogical(fontSize))
 
     return Font(owning: CreateFontIndirectW(&lfFont))
   }
@@ -407,7 +407,7 @@ public class Font {
       return 0.0
     }
 
-    return LogicalToPoint(lfFont.lfHeight)
+    return LogicalToPoint(Int32(lfFont.lfHeight))
   }
 
   /// The top y-coordinate, offset from the baseline, of the font's longest
diff --git a/Sources/SwiftWin32/Views and Controls/Control.swift b/Sources/SwiftWin32/Views and Controls/Control.swift
index f893ab3e..c84ec786 100644
--- a/Sources/SwiftWin32/Views and Controls/Control.swift	
+++ b/Sources/SwiftWin32/Views and Controls/Control.swift	
@@ -262,27 +262,27 @@ extension Control.Event {
 
   /// All touch events.
   public static var allTouchEvents: Control.Event {
-    Control.Event(rawValue: 0x00000fff)
+    Control.Event(rawValue: RawValue(bitPattern: 0x00000fff))
   }
 
   /// All editing touches for `TextField` objects.
   public static var allEditingEvents: Control.Event {
-    Control.Event(rawValue: 0x000f0000)
+    Control.Event(rawValue: RawValue(bitPattern: 0x000f0000))
   }
 
   /// A range of control-event values available for application use.
   public static var applicationReserved: Control.Event {
-    Control.Event(rawValue: 0x0f000000)
+    Control.Event(rawValue: RawValue(bitPattern: 0x0f000000))
   }
 
   /// A range of control-event values reserved for internal framework use.
   public static var systemReserved: Control.Event {
-    Control.Event(rawValue: 0xf0000000)
+    Control.Event(rawValue: RawValue(bitPattern: 0xf0000000))
   }
 
   /// All events, including system events.
   public static var allEvents: Control.Event {
-    Control.Event(rawValue: 0xffffffff)
+    Control.Event(rawValue: RawValue(bitPattern: 0xffffffff))
   }
 }
 
diff --git a/Sources/SwiftWin32/Views and Controls/PickerView.swift b/Sources/SwiftWin32/Views and Controls/PickerView.swift
index 8fc1e6ac..df5cf243 100644
--- a/Sources/SwiftWin32/Views and Controls/PickerView.swift	
+++ b/Sources/SwiftWin32/Views and Controls/PickerView.swift	
@@ -25,7 +25,7 @@ private let SwiftPickerViewProxyWindowProc: WNDPROC = { (hWnd, uMsg, wParam, lPa
     switch lpDrawItem.pointee.itemAction {
     case UINT(ODA_SELECT):
       _ = DrawFocusRect(lpDrawItem.pointee.hDC, &lpDrawItem.pointee.rcItem)
-      if lpDrawItem.pointee.itemState & DWORD(ODS_SELECTED) == DWORD(ODS_SELECTED) {
+      if DWORD(lpDrawItem.pointee.itemState) & DWORD(ODS_SELECTED) == DWORD(ODS_SELECTED) {
         // If the item is selected, we have drawn the focus rectangle and the
         // operation is complete.
         return LRESULT(1)
@@ -38,8 +38,8 @@ private let SwiftPickerViewProxyWindowProc: WNDPROC = { (hWnd, uMsg, wParam, lPa
       if let view = unsafeBitCast(lpDrawItem.pointee.itemData,
                                   to: AnyObject.self) as? View {
         let rctRect: RECT = lpDrawItem.pointee.rcItem
-        _ = SetWindowPos(view.hWnd, nil, rctRect.left, rctRect.top, 0, 0,
-                         UINT(SWP_NOSIZE))
+        _ = SetWindowPos(view.hWnd, nil, CInt(rctRect.left), CInt(rctRect.top),
+                         0, 0, UINT(SWP_NOSIZE))
         // Setting `isHidden` is necessary for Views generated after initial
         // call to `Window.makeKeyAndVisible()`
         if IsWindowVisible(GetParent(view.hWnd)) && !IsWindowVisible(view.hWnd) {
@@ -117,8 +117,8 @@ private let SwiftPickerViewWindowProc: SUBCLASSPROC = { (hWnd, uMsg, wParam, lPa
         DeviceContextHandle(owning: GetDC(view.hWnd))
     let hBitmap: BitmapHandle =
         BitmapHandle(owning: CreateCompatibleBitmap(hDCItem.value,
-                                                    rcClient.right - rcClient.left,
-                                                    rcClient.bottom - rcClient.top))
+                                                    CInt(rcClient.right - rcClient.left),
+                                                    CInt(rcClient.bottom - rcClient.top)))
 
     let hDCMemory: DeviceContextHandle =
         DeviceContextHandle(owning: CreateCompatibleDC(nil))
@@ -133,10 +133,10 @@ private let SwiftPickerViewWindowProc: SUBCLASSPROC = { (hWnd, uMsg, wParam, lPa
     let hDC: DeviceContextHandle =
         DeviceContextHandle(owning: GetDC(hWnd))
 
-    _ = BitBlt(hDC.value, cbiInfo.rcItem.left, cbiInfo.rcItem.top,
-               cbiInfo.rcItem.right - cbiInfo.rcItem.left,
-               cbiInfo.rcItem.bottom - cbiInfo.rcItem.top, hDCMemory.value,
-               0, 0, UINT(SRCCOPY))
+    _ = BitBlt(hDC.value, CInt(cbiInfo.rcItem.left), CInt(cbiInfo.rcItem.top),
+               CInt(cbiInfo.rcItem.right - cbiInfo.rcItem.left),
+               CInt(cbiInfo.rcItem.bottom - cbiInfo.rcItem.top),
+               hDCMemory.value, 0, 0, DWORD(SRCCOPY))
 
     return lResult
 
diff --git a/Sources/SwiftWin32/Views and Controls/Stepper.swift b/Sources/SwiftWin32/Views and Controls/Stepper.swift
index 88d5b588..09e129cb 100644
--- a/Sources/SwiftWin32/Views and Controls/Stepper.swift	
+++ b/Sources/SwiftWin32/Views and Controls/Stepper.swift	
@@ -54,7 +54,7 @@ private class StepperProxy {
 public class Stepper: Control {
   private static let `class`: WindowClass = WindowClass(named: UPDOWN_CLASS)
   private static let style: WindowStyle =
-      (base: UInt32(UDS_HORZ) | WS_POPUP | WS_TABSTOP, extended: 0)
+      (base: DWORD(UDS_HORZ) | WS_POPUP | WS_TABSTOP, extended: 0)
 
   private static var proxy: StepperProxy = StepperProxy()
 
@@ -75,10 +75,10 @@ public class Stepper: Control {
   /// A boolean value that determines whether the stepper can wrap its value to
   /// the minimum or maximum value when incrementing and decrementing the value.
   public var wraps: Bool {
-    get { self.GWL_STYLE & UDS_WRAP == UDS_WRAP }
+    get { self.GWL_STYLE & LONG(UDS_WRAP) == LONG(UDS_WRAP) }
     set {
-      self.GWL_STYLE = newValue ? self.GWL_STYLE | UDS_WRAP
-                                : self.GWL_STYLE & ~UDS_WRAP
+      self.GWL_STYLE = newValue ? self.GWL_STYLE | LONG(UDS_WRAP)
+                                : self.GWL_STYLE & ~LONG(UDS_WRAP)
     }
   }
 
@@ -137,7 +137,7 @@ public class Stepper: Control {
         SendMessageW(self.hWnd, UINT(UDM_GETACCEL),
                      WPARAM(1), LPARAM(UInt(bitPattern: $0)))
       }
-      value.nInc = DWORD(newValue)
+      value.nInc = UINT(newValue)
       _ = withUnsafeMutablePointer(to: &value) {
         SendMessageW(self.hWnd, UINT(UDM_SETACCEL),
                      WPARAM(1), LPARAM(UInt(bitPattern: $0)))
diff --git a/Sources/SwiftWin32/Views and Controls/Table Views/TableView.swift b/Sources/SwiftWin32/Views and Controls/Table Views/TableView.swift
index 8a471c08..89f5ca99 100644
--- a/Sources/SwiftWin32/Views and Controls/Table Views/TableView.swift	
+++ b/Sources/SwiftWin32/Views and Controls/Table Views/TableView.swift	
@@ -25,8 +25,8 @@ private let SwiftTableViewProxyWindowProc: WNDPROC = { (hWnd, uMsg, wParam, lPar
       if let view = unsafeBitCast(lpDrawItem.pointee.itemData,
                                   to: AnyObject.self) as? View {
         let rctRect: RECT = lpDrawItem.pointee.rcItem
-        _ = SetWindowPos(view.hWnd, nil, rctRect.left, rctRect.top, 0, 0,
-                         UINT(SWP_NOSIZE))
+        _ = SetWindowPos(view.hWnd, nil, CInt(rctRect.left), CInt(rctRect.top),
+                         0, 0, UINT(SWP_NOSIZE))
 
         // Setting `isHidden` is necessary for TableCells generated after
         // initial call to `Window.makeKeyAndVisible()`
diff --git a/Sources/SwiftWin32/Views and Controls/TextView.swift b/Sources/SwiftWin32/Views and Controls/TextView.swift
index 8cda12d3..e34b1e82 100644
--- a/Sources/SwiftWin32/Views and Controls/TextView.swift	
+++ b/Sources/SwiftWin32/Views and Controls/TextView.swift	
@@ -37,13 +37,13 @@ public class TextView: View {
     // Disable compatibility with the original Rich Edit and use the extended
     // text limit.
     _ = SendMessageW(self.hWnd, UINT(EM_EXLIMITTEXT),
-                     WPARAM(0), LPARAM(bitPattern: UInt64(bitPattern: -1)))
+                     WPARAM(0), LPARAM(UInt(bitPattern: -1)))
   }
 
   public func scrollRangeToVisible(_ range: NSRange) {
     SendMessageW(hWnd, UINT(EM_SETSEL), WPARAM(range.location),
                  LPARAM(range.location + range.length))
-    SendMessageW(hWnd, UINT(EM_SETSEL), UInt64(bitPattern: -1), -1)
+    SendMessageW(hWnd, UINT(EM_SETSEL), WPARAM(bitPattern: -1), -1)
     SendMessageW(hWnd, UINT(EM_SCROLLCARET), 0, 0)
   }