diff --git a/Source/DiabloUI/settingsmenu.cpp b/Source/DiabloUI/settingsmenu.cpp
index 399b36687..2a7080a9b 100644
--- a/Source/DiabloUI/settingsmenu.cpp
+++ b/Source/DiabloUI/settingsmenu.cpp
@@ -304,9 +304,25 @@ void UiSettingsMenu()
 			eventHandler = [](SDL_Event &event) {
 				if (SelectedItem != IndexKeyInput)
 					return false;
-				if (event.type != SDL_KEYDOWN)
-					return false;
-				int key = TranslateSdlKey(event.key.keysym);
+				int key = DVL_VK_INVALID;
+				switch (event.type) {
+				case SDL_KEYDOWN:
+					key = TranslateSdlKey(event.key.keysym);
+					break;
+				case SDL_MOUSEBUTTONDOWN:
+					switch (event.button.button) {
+					case SDL_BUTTON_MIDDLE:
+						key = DVL_VK_MBUTTON;
+						break;
+					case SDL_BUTTON_X1:
+						key = DVL_VK_X1BUTTON;
+						break;
+					case SDL_BUTTON_X2:
+						key = DVL_VK_X2BUTTON;
+						break;
+					}
+					break;
+				}
 				// Ignore unknown keys
 				if (key == DVL_VK_INVALID || key == -1)
 					return false;
diff --git a/Source/diablo.cpp b/Source/diablo.cpp
index 265d688d6..cb353813e 100644
--- a/Source/diablo.cpp
+++ b/Source/diablo.cpp
@@ -623,6 +623,24 @@ void GameEventHandler(uint32_t uMsg, int32_t wParam, int32_t lParam)
 			sgbMouseDown = CLICK_NONE;
 		}
 		return;
+	case DVL_WM_MBUTTONDOWN:
+		sgOptions.Keymapper.KeyPressed(DVL_VK_MBUTTON);
+		return;
+	case DVL_WM_MBUTTONUP:
+		sgOptions.Keymapper.KeyReleased(DVL_VK_MBUTTON);
+		return;
+	case DVL_WM_X1BUTTONDOWN:
+		sgOptions.Keymapper.KeyPressed(DVL_VK_X1BUTTON);
+		return;
+	case DVL_WM_X1BUTTONUP:
+		sgOptions.Keymapper.KeyReleased(DVL_VK_X1BUTTON);
+		return;
+	case DVL_WM_X2BUTTONDOWN:
+		sgOptions.Keymapper.KeyPressed(DVL_VK_X2BUTTON);
+		return;
+	case DVL_WM_X2BUTTONUP:
+		sgOptions.Keymapper.KeyReleased(DVL_VK_X2BUTTON);
+		return;
 	case DVL_WM_CAPTURECHANGED:
 		sgbMouseDown = CLICK_NONE;
 		LastMouseButtonAction = MouseActionType::None;
diff --git a/Source/miniwin/miniwin.h b/Source/miniwin/miniwin.h
index fc61d6722..d75cc9918 100644
--- a/Source/miniwin/miniwin.h
+++ b/Source/miniwin/miniwin.h
@@ -78,6 +78,12 @@ void ClearMessageQueue();
 #define DVL_WM_LBUTTONUP 0x0202
 #define DVL_WM_RBUTTONDOWN 0x0204
 #define DVL_WM_RBUTTONUP 0x0205
+#define DVL_WM_MBUTTONDOWN 0x0206
+#define DVL_WM_MBUTTONUP 0x0207
+#define DVL_WM_X1BUTTONDOWN 0x0208
+#define DVL_WM_X1BUTTONUP 0x0209
+#define DVL_WM_X2BUTTONDOWN 0x020A
+#define DVL_WM_X2BUTTONUP 0x020B
 
 #define DVL_WM_KEYDOWN 0x0100
 #define DVL_WM_KEYUP 0x0101
@@ -97,6 +103,9 @@ void ClearMessageQueue();
 //
 // ref: https://docs.microsoft.com/en-us/windows/win32/inputdev/virtual-key-codes
 #define DVL_VK_INVALID 0     // Invalid key
+#define DVL_VK_MBUTTON 0x04  // Middle mouse button (three-button mouse)
+#define DVL_VK_X1BUTTON 0x05 // X1 mouse button
+#define DVL_VK_X2BUTTON 0x06 // X2 mouse button
 #define DVL_VK_BACK 0x08     // BACKSPACE key
 #define DVL_VK_TAB 0x09      // TAB key
 #define DVL_VK_RETURN 0x0D   // ENTER key
diff --git a/Source/miniwin/misc_msg.cpp b/Source/miniwin/misc_msg.cpp
index a1cb5539a..216e104a0 100644
--- a/Source/miniwin/misc_msg.cpp
+++ b/Source/miniwin/misc_msg.cpp
@@ -513,26 +513,62 @@ bool FetchMessage_Real(tagMSG *lpMsg)
 		break;
 	case SDL_MOUSEBUTTONDOWN: {
 		int button = e.button.button;
-		if (button == SDL_BUTTON_LEFT) {
+		switch (button) {
+		case SDL_BUTTON_LEFT:
 			lpMsg->message = DVL_WM_LBUTTONDOWN;
 			lpMsg->lParam = PositionForMouse(e.button.x, e.button.y);
 			lpMsg->wParam = KeystateForMouse(DVL_MK_LBUTTON);
-		} else if (button == SDL_BUTTON_RIGHT) {
+			break;
+		case SDL_BUTTON_RIGHT:
 			lpMsg->message = DVL_WM_RBUTTONDOWN;
 			lpMsg->lParam = PositionForMouse(e.button.x, e.button.y);
 			lpMsg->wParam = KeystateForMouse(DVL_MK_RBUTTON);
+			break;
+		case SDL_BUTTON_MIDDLE:
+			lpMsg->message = DVL_WM_MBUTTONDOWN;
+			lpMsg->lParam = PositionForMouse(e.button.x, e.button.y);
+			lpMsg->wParam = KeystateForMouse(0);
+			break;
+		case SDL_BUTTON_X1:
+			lpMsg->message = DVL_WM_X1BUTTONDOWN;
+			lpMsg->lParam = PositionForMouse(e.button.x, e.button.y);
+			lpMsg->wParam = KeystateForMouse(0);
+			break;
+		case SDL_BUTTON_X2:
+			lpMsg->message = DVL_WM_X2BUTTONDOWN;
+			lpMsg->lParam = PositionForMouse(e.button.x, e.button.y);
+			lpMsg->wParam = KeystateForMouse(0);
+			break;
 		}
 	} break;
 	case SDL_MOUSEBUTTONUP: {
 		int button = e.button.button;
-		if (button == SDL_BUTTON_LEFT) {
+		switch (button) {
+		case SDL_BUTTON_LEFT:
 			lpMsg->message = DVL_WM_LBUTTONUP;
 			lpMsg->lParam = PositionForMouse(e.button.x, e.button.y);
 			lpMsg->wParam = KeystateForMouse(0);
-		} else if (button == SDL_BUTTON_RIGHT) {
+			break;
+		case SDL_BUTTON_RIGHT:
 			lpMsg->message = DVL_WM_RBUTTONUP;
 			lpMsg->lParam = PositionForMouse(e.button.x, e.button.y);
 			lpMsg->wParam = KeystateForMouse(0);
+			break;
+		case SDL_BUTTON_MIDDLE:
+			lpMsg->message = DVL_WM_MBUTTONUP;
+			lpMsg->lParam = PositionForMouse(e.button.x, e.button.y);
+			lpMsg->wParam = KeystateForMouse(0);
+			break;
+		case SDL_BUTTON_X1:
+			lpMsg->message = DVL_WM_X1BUTTONUP;
+			lpMsg->lParam = PositionForMouse(e.button.x, e.button.y);
+			lpMsg->wParam = KeystateForMouse(0);
+			break;
+		case SDL_BUTTON_X2:
+			lpMsg->message = DVL_WM_X2BUTTONUP;
+			lpMsg->lParam = PositionForMouse(e.button.x, e.button.y);
+			lpMsg->wParam = KeystateForMouse(0);
+			break;
 		}
 	} break;
 #ifndef USE_SDL1
diff --git a/Source/options.cpp b/Source/options.cpp
index f3013c880..1f4044317 100644
--- a/Source/options.cpp
+++ b/Source/options.cpp
@@ -1056,6 +1056,9 @@ KeymapperOptions::KeymapperOptions()
 	keyIDToKeyName.emplace(DVL_VK_SNAPSHOT, "PRINT");
 	keyIDToKeyName.emplace(DVL_VK_PAUSE, "PAUSE");
 	keyIDToKeyName.emplace(DVL_VK_TAB, "TAB");
+	keyIDToKeyName.emplace(DVL_VK_MBUTTON, "MMOUSE");
+	keyIDToKeyName.emplace(DVL_VK_X1BUTTON, "X1MOUSE");
+	keyIDToKeyName.emplace(DVL_VK_X2BUTTON, "X2MOUSE");
 
 	keyNameToKeyID.reserve(keyIDToKeyName.size());
 	for (const auto &kv : keyIDToKeyName) {