diff --git a/ControllerUSB/include/IUSBEndpoint.h b/ControllerUSB/include/IUSBEndpoint.h
index a5a38f0..a36a594 100644
--- a/ControllerUSB/include/IUSBEndpoint.h
+++ b/ControllerUSB/include/IUSBEndpoint.h
@@ -28,7 +28,7 @@ public:
     virtual void Close() = 0;
 
     //This will read from the inBuffer pointer for the specified size and write it to the endpoint.
-    virtual Status Write(void *inBuffer, size_t bufferSize) = 0;
+    virtual Status Write(const void *inBuffer, size_t bufferSize) = 0;
 
     //This will read from the endpoint and put the data in the outBuffer pointer for the specified size.
     virtual Status Read(void *outBuffer, size_t bufferSize) = 0;
diff --git a/SwitchUSB/include/SwitchUSBEndpoint.h b/SwitchUSB/include/SwitchUSBEndpoint.h
index d474fb2..3033c6a 100644
--- a/SwitchUSB/include/SwitchUSBEndpoint.h
+++ b/SwitchUSB/include/SwitchUSBEndpoint.h
@@ -22,7 +22,7 @@ public:
     virtual void Close();
 
     //buffer should point to the data array, and only the specified size will be read.
-    virtual Result Write(void *inBuffer, size_t bufferSize);
+    virtual Result Write(const void *inBuffer, size_t bufferSize);
 
     //The data received will be put in the outBuffer array for the length of the specified size.
     virtual Result Read(void *outBuffer, size_t bufferSize);
diff --git a/SwitchUSB/source/SwitchUSBEndpoint.cpp b/SwitchUSB/source/SwitchUSBEndpoint.cpp
index 19482ae..de84b19 100644
--- a/SwitchUSB/source/SwitchUSBEndpoint.cpp
+++ b/SwitchUSB/source/SwitchUSBEndpoint.cpp
@@ -28,7 +28,7 @@ void SwitchUSBEndpoint::Close()
     usbHsEpClose(&m_epSession);
 }
 
-Result SwitchUSBEndpoint::Write(void *inBuffer, size_t bufferSize)
+Result SwitchUSBEndpoint::Write(const void *inBuffer, size_t bufferSize)
 {
     Result rc = -1;
     if (m_buffer != nullptr)
@@ -38,7 +38,7 @@ Result SwitchUSBEndpoint::Write(void *inBuffer, size_t bufferSize)
 
         for (size_t byte = 0; byte != bufferSize; ++byte)
         {
-            static_cast<uint8_t *>(m_buffer)[byte] = static_cast<uint8_t *>(inBuffer)[byte];
+            static_cast<uint8_t *>(m_buffer)[byte] = static_cast<const uint8_t *>(inBuffer)[byte];
         }
 
         rc = usbHsEpPostBuffer(&m_epSession, m_buffer, bufferSize, &transferredSize);