diff --git a/app/gui/PcView.qml b/app/gui/PcView.qml
index e26ea563..8b646551 100644
--- a/app/gui/PcView.qml
+++ b/app/gui/PcView.qml
@@ -46,6 +46,12 @@ GridView {
             noHwDecoderDialog.open()
         }
 
+        var unmappedGamepads = prefs.getUnmappedGamepads()
+        if (unmappedGamepads) {
+            unmappedGamepadDialog.unmappedGamepads = unmappedGamepads
+            unmappedGamepadDialog.open()
+        }
+
         // Don't show any highlighted item until interacting with them
         currentIndex = -1
     }
@@ -244,6 +250,20 @@ GridView {
         }
     }
 
+    MessageDialog {
+        id: unmappedGamepadDialog
+        property string unmappedGamepads : ""
+        modality:Qt.WindowModal
+        icon: StandardIcon.Warning
+        standardButtons: StandardButton.Ok | StandardButton.Help
+        text: "Moonlight detected gamepads without a proper mapping. " +
+              "The following gamepads will not function until this is resolved: " + unmappedGamepads + "\n\n" +
+              "Click the Help button for information on how to map your gamepads."
+        onHelp: {
+            Qt.openUrlExternally("https://github.com/moonlight-stream/moonlight-docs/wiki/Gamepad-Mapping");
+        }
+    }
+
     MessageDialog {
         id: pairDialog
         // don't allow edits to the rest of the window while open
diff --git a/app/settings/streamingpreferences.cpp b/app/settings/streamingpreferences.cpp
index 638b4c3a..370a7ace 100644
--- a/app/settings/streamingpreferences.cpp
+++ b/app/settings/streamingpreferences.cpp
@@ -99,6 +99,11 @@ bool StreamingPreferences::isWow64()
 #endif
 }
 
+QString StreamingPreferences::getUnmappedGamepads()
+{
+    return SdlInputHandler::getUnmappedGamepads();
+}
+
 int StreamingPreferences::getMaximumStreamingFrameRate()
 {
     // Never let the maximum drop below 60 FPS
diff --git a/app/settings/streamingpreferences.h b/app/settings/streamingpreferences.h
index 120d33e7..a0809632 100644
--- a/app/settings/streamingpreferences.h
+++ b/app/settings/streamingpreferences.h
@@ -27,6 +27,8 @@ public:
 
     Q_INVOKABLE QRect getNativeResolution(int displayIndex);
 
+    Q_INVOKABLE QString getUnmappedGamepads();
+
     void reload();
 
     enum AudioConfig
diff --git a/app/streaming/input.cpp b/app/streaming/input.cpp
index 4f7eb698..abb66035 100644
--- a/app/streaming/input.cpp
+++ b/app/streaming/input.cpp
@@ -668,9 +668,37 @@ void SdlInputHandler::handleControllerDeviceEvent(SDL_ControllerDeviceEvent* eve
     }
 }
 
+void SdlInputHandler::handleJoystickArrivalEvent(SDL_JoyDeviceEvent* event)
+{
+    SDL_assert(event->type == SDL_JOYDEVICEADDED);
+
+    if (!SDL_IsGameController(event->which)) {
+        char guidStr[33];
+        SDL_JoystickGetGUIDString(SDL_JoystickGetDeviceGUID(event->which),
+                                  guidStr, sizeof(guidStr));
+        const char* name = SDL_JoystickNameForIndex(event->which);
+        SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
+                    "Joystick discovered with no mapping: %s %s",
+                    name ? name : "<UNKNOWN>",
+                    guidStr);
+        SDL_Joystick* joy = SDL_JoystickOpen(event->which);
+        if (joy != nullptr) {
+            SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
+                        "Number of axes: %d | Number of buttons: %d | Number of hats: %d",
+                        SDL_JoystickNumAxes(joy), SDL_JoystickNumButtons(joy),
+                        SDL_JoystickNumHats(joy));
+            SDL_JoystickClose(joy);
+        }
+        else {
+            SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
+                        "Unable to open joystick for query: %s",
+                        SDL_GetError());
+        }
+    }
+}
+
 int SdlInputHandler::getAttachedGamepadMask()
 {
-    int i;
     int count;
     int mask;
 
@@ -680,7 +708,7 @@ int SdlInputHandler::getAttachedGamepadMask()
     }
 
     count = mask = 0;
-    for (i = 0; i < SDL_NumJoysticks(); i++) {
+    for (int i = 0; i < SDL_NumJoysticks(); i++) {
         if (SDL_IsGameController(i)) {
             mask |= (1 << count++);
         }
@@ -688,3 +716,58 @@ int SdlInputHandler::getAttachedGamepadMask()
 
     return mask;
 }
+
+QString SdlInputHandler::getUnmappedGamepads()
+{
+    QString ret;
+
+    if (SDL_InitSubSystem(SDL_INIT_GAMECONTROLLER) != 0) {
+        SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
+                     "SDL_InitSubSystem(SDL_INIT_GAMECONTROLLER) failed: %s",
+                     SDL_GetError());
+    }
+
+    for (int i = 0; i < SDL_NumJoysticks(); i++) {
+        if (!SDL_IsGameController(i)) {
+            char guidStr[33];
+            SDL_JoystickGetGUIDString(SDL_JoystickGetDeviceGUID(i),
+                                      guidStr, sizeof(guidStr));
+            const char* name = SDL_JoystickNameForIndex(i);
+            SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
+                        "Unmapped joystick: %s %s",
+                        name ? name : "<UNKNOWN>",
+                        guidStr);
+            SDL_Joystick* joy = SDL_JoystickOpen(i);
+            if (joy != nullptr) {
+                int numButtons = SDL_JoystickNumButtons(joy);
+                int numHats = SDL_JoystickNumHats(joy);
+                int numAxes = SDL_JoystickNumAxes(joy);
+
+                SDL_LogInfo(SDL_LOG_CATEGORY_APPLICATION,
+                            "Number of axes: %d | Number of buttons: %d | Number of hats: %d",
+                            numAxes, numButtons, numHats);
+
+                if (numAxes >= 4 && numButtons >= 8 && numHats <= 1) {
+                    SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
+                                "Joystick likely to be an unmapped game controller");
+                    if (!ret.isEmpty()) {
+                        ret += ", ";
+                    }
+
+                    ret += name;
+                }
+
+                SDL_JoystickClose(joy);
+            }
+            else {
+                SDL_LogWarn(SDL_LOG_CATEGORY_APPLICATION,
+                            "Unable to open joystick for query: %s",
+                            SDL_GetError());
+            }
+        }
+    }
+
+    SDL_QuitSubSystem(SDL_INIT_GAMECONTROLLER);
+
+    return ret;
+}
diff --git a/app/streaming/input.h b/app/streaming/input.h
index b0bd5987..081d1df6 100644
--- a/app/streaming/input.h
+++ b/app/streaming/input.h
@@ -39,8 +39,13 @@ public:
 
     void handleControllerDeviceEvent(SDL_ControllerDeviceEvent* event);
 
+    void handleJoystickArrivalEvent(SDL_JoyDeviceEvent* event);
+
     int getAttachedGamepadMask();
 
+    static
+    QString getUnmappedGamepads();
+
 private:
     GamepadState*
     findStateForGamepad(SDL_JoystickID id);
diff --git a/app/streaming/session.cpp b/app/streaming/session.cpp
index 2b617ccd..6738f4e6 100644
--- a/app/streaming/session.cpp
+++ b/app/streaming/session.cpp
@@ -525,6 +525,11 @@ bool Session::validateLaunch()
         emitLaunchWarning("Failed to open audio device. Audio will be unavailable during this session.");
     }
 
+    // Check for unmapped gamepads
+    if (!SdlInputHandler::getUnmappedGamepads().isEmpty()) {
+        emitLaunchWarning("An attached gamepad has no mapping and won't be usable. Visit the Moonlight help to resolve this.");
+    }
+
     if (m_Preferences->videoDecoderSelection == StreamingPreferences::VDS_FORCE_HARDWARE &&
             !isHardwareDecodeAvailable(m_Preferences->videoDecoderSelection,
                                        m_StreamConfig.supportsHevc ? VIDEO_FORMAT_H265 : VIDEO_FORMAT_H264,
@@ -1107,13 +1112,12 @@ void Session::exec(int displayOriginX, int displayOriginY)
         case SDL_CONTROLLERDEVICEREMOVED:
             inputHandler.handleControllerDeviceEvent(&event.cdevice);
             break;
+        case SDL_JOYDEVICEADDED:
+            inputHandler.handleJoystickArrivalEvent(&event.jdevice);
+            break;
         }
     }
 
-    SDL_LogError(SDL_LOG_CATEGORY_APPLICATION,
-                 "SDL_WaitEvent() failed: %s",
-                 SDL_GetError());
-
 DispatchDeferredCleanup:
 #ifdef Q_OS_WIN32
     // HACK: See comment above