diff --git a/esp3d/src/modules/telnet/telnet_server.cpp b/esp3d/src/modules/telnet/telnet_server.cpp
index a7469b6c..0e894ce2 100644
--- a/esp3d/src/modules/telnet/telnet_server.cpp
+++ b/esp3d/src/modules/telnet/telnet_server.cpp
@@ -269,7 +269,7 @@ size_t Telnet_Server::write(const uint8_t *buffer, size_t size)
     return 0;
 }
 
-uint Telnet_Server::availableForWrite()
+int Telnet_Server::availableForWrite()
 {
     if (!isConnected()) {
         return 0;
diff --git a/esp3d/src/modules/telnet/telnet_server.h b/esp3d/src/modules/telnet/telnet_server.h
index 6aacd5da..7d5de5fe 100644
--- a/esp3d/src/modules/telnet/telnet_server.h
+++ b/esp3d/src/modules/telnet/telnet_server.h
@@ -62,7 +62,7 @@ public:
         return write((uint8_t) n);
     }
     int available();
-    uint availableForWrite();
+    int availableForWrite();
     void flush();
     int read(void);
     size_t readBytes (uint8_t * sbuf, size_t len);
diff --git a/esp3d/src/modules/websocket/websocket_server.cpp b/esp3d/src/modules/websocket/websocket_server.cpp
index c27d8300..a113d1fb 100644
--- a/esp3d/src/modules/websocket/websocket_server.cpp
+++ b/esp3d/src/modules/websocket/websocket_server.cpp
@@ -135,7 +135,7 @@ int WebSocket_Server::available()
 {
     return _RXbufferSize;
 }
-uint WebSocket_Server::availableForWrite()
+int WebSocket_Server::availableForWrite()
 {
     return TXBUFFERSIZE -_TXbufferSize;
 }
diff --git a/esp3d/src/modules/websocket/websocket_server.h b/esp3d/src/modules/websocket/websocket_server.h
index d3edd6eb..54692943 100644
--- a/esp3d/src/modules/websocket/websocket_server.h
+++ b/esp3d/src/modules/websocket/websocket_server.h
@@ -62,7 +62,7 @@ public:
     }
     void end();
     int available();
-    uint availableForWrite();
+    int availableForWrite();
     void pushMSG (const char * data);
     void pushMSG (uint num, const char * data);
     void flush(void);