diff --git a/src/PPPOSClient.cpp b/src/PPPOSClient.cpp
index 65608fb..c88caf9 100644
--- a/src/PPPOSClient.cpp
+++ b/src/PPPOSClient.cpp
@@ -233,18 +233,21 @@ uint8_t PPPOSClient::connected() {
 int PPPOSClient::read(uint8_t *buf, size_t size) {
     if (!_connected) return -1;
     int res = -1;
+    int j = 0;
     if (available()){
-        int j = 0;
     	for (int i = _startPos; i < _endPos; i++) {
             if (j < size) {
                 buf[j] = RxBuffer[i]; 
             } else {
-                res = j; 
-                _startPos += j;
+                break;
             }
             j++;
         }
     }
+    if (j > 0) {
+	    _startPos += j;
+	    res = j;
+    }
     return res;
 }
 	  
@@ -263,4 +266,4 @@ int PPPOSClient::peek() {
       }
    }
    return RxBuffer[_startPos];
-}
\ No newline at end of file
+}