diff --git a/src/PowerTapUtil.cpp b/src/PowerTapUtil.cpp
index 8948de312..efc958a96 100644
--- a/src/PowerTapUtil.cpp
+++ b/src/PowerTapUtil.cpp
@@ -131,6 +131,9 @@ PowerTapUtil::unpack_data(unsigned char *buf, double rec_int_secs,
         else
         {
             *watts = ((buf[2] & 0x0f) << 8) | buf[3];
+            if(*watts >= 4000.00)
+                *watts = 0.0;
+            
             *cad = buf[4];
             if (*cad == 0xff)
                 *cad = 0;