diff --git a/hardware/arduino/cores/arduino/Stream.cpp b/hardware/arduino/cores/arduino/Stream.cpp
index 5fad8dd67..3d5b90529 100644
--- a/hardware/arduino/cores/arduino/Stream.cpp
+++ b/hardware/arduino/cores/arduino/Stream.cpp
@@ -99,25 +99,27 @@ bool Stream::findUntil(char *target, size_t targetLen, char *terminator, size_t
   size_t index = 0;  // maximum target string length is 64k bytes!
   size_t termIndex = 0;
   int c;
-
+  
   if( *target == 0)
-     return true;   // return true if target is a null string
+    return true;   // return true if target is a null string
   while( (c = timedRead()) > 0){
+    
+    if(c != target[index])
+      index = 0; // reset index if any char does not match
+    
     if( c == target[index]){
-    //////Serial.print("found "); Serial.write(c); Serial.print("index now"); Serial.println(index+1);
+      //////Serial.print("found "); Serial.write(c); Serial.print("index now"); Serial.println(index+1);
       if(++index >= targetLen){ // return true if all chars in the target match
         return true;
       }
     }
-    else{
-      index = 0;  // reset index if any char does not match
-    }
+    
     if(termLen > 0 && c == terminator[termIndex]){
-       if(++termIndex >= termLen)
-         return false;       // return false if terminate string found before target string
+      if(++termIndex >= termLen)
+        return false;       // return false if terminate string found before target string
     }
     else
-        termIndex = 0;
+      termIndex = 0;
   }
   return false;
 }