diff --git a/hiduniversal.h b/hiduniversal.h
index 3aa4690a..757f6243 100644
--- a/hiduniversal.h
+++ b/hiduniversal.h
@@ -40,7 +40,7 @@ class HIDUniversal : public USBHID {
                         uint8_t bmAltSet : 3;
                         uint8_t bmProtocol : 2;
                 };
-                uint8_t epIndex[maxEpPerInterface];
+                uint8_t epIndex[maxEpPerInterface + 1]; // We need to make room for the control endpoint as well
         };
 
         uint8_t bConfNum; // configuration number
diff --git a/usbhid.h b/usbhid.h
index 791bed35..cf74f57d 100644
--- a/usbhid.h
+++ b/usbhid.h
@@ -151,7 +151,7 @@ protected:
 
         static const uint8_t maxHidInterfaces = 3;
         static const uint8_t maxEpPerInterface = 2;
-        static const uint8_t totalEndpoints = (maxHidInterfaces * maxEpPerInterface + 1);
+        static const uint8_t totalEndpoints = (maxHidInterfaces * maxEpPerInterface + 1); // We need to make room for the control endpoint
 
         void PrintEndpointDescriptor(const USB_ENDPOINT_DESCRIPTOR* ep_ptr);
         void PrintHidDescriptor(const USB_HID_DESCRIPTOR *pDesc);