diff --git a/hardware/arduino/cores/arduino/Stream.cpp b/hardware/arduino/cores/arduino/Stream.cpp
index f21a411f83b..170c07b8e37 100644
--- a/hardware/arduino/cores/arduino/Stream.cpp
+++ b/hardware/arduino/cores/arduino/Stream.cpp
@@ -199,7 +199,7 @@ float Stream::parseFloat(char skipChar){
     read();  // consume the character we got with peek
     c = timedPeek();
   }
-  while( (c >= '0' && c <= '9')  || c == '.' || c == skipChar );
+  while( (c >= '0' && c <= '9')  || (c == '.' && !isFraction) || c == skipChar );
 
   if(isNegative)
     value = -value;