diff --git a/libraries/DHTstable/dht.cpp b/libraries/DHTstable/dht.cpp
index 114941f1..d1951067 100644
--- a/libraries/DHTstable/dht.cpp
+++ b/libraries/DHTstable/dht.cpp
@@ -6,6 +6,7 @@
 //     URL: https://github.com/RobTillaart/Arduino/tree/master/libraries/DHTstable
 //
 // HISTORY:
+// 0.2.1  2017-09-20 fix https://github.com/RobTillaart/Arduino/issues/80
 // 0.2.0  2017-07-24 fix https://github.com/RobTillaart/Arduino/issues/31 + 33
 // 0.1.13 fix negative temperature
 // 0.1.12 support DHT33 and DHT44 initial version
@@ -54,10 +55,11 @@ int dht::read11(uint8_t pin)
     temperature = bits[2];  // bits[3] == 0;
 
     // TEST CHECKSUM
-    // bits[1] && bits[3] both 0
-    uint8_t sum = bits[0] + bits[2];
-    if (bits[4] != sum) return DHTLIB_ERROR_CHECKSUM;
-
+    uint8_t sum = bits[0] + bits[1] + bits[2] + bits[3];
+    if (bits[4] != sum)
+    {
+      return DHTLIB_ERROR_CHECKSUM;
+    }
     return DHTLIB_OK;
 }
 
diff --git a/libraries/DHTstable/dht.h b/libraries/DHTstable/dht.h
index bce8040a..855daac8 100644
--- a/libraries/DHTstable/dht.h
+++ b/libraries/DHTstable/dht.h
@@ -1,7 +1,7 @@
 //
 //    FILE: dht.h
 //  AUTHOR: Rob Tillaart
-// VERSION: 0.2.0
+// VERSION: 0.2.1
 // PURPOSE: DHT Temperature & Humidity Sensor library for Arduino
 //     URL: https://github.com/RobTillaart/Arduino/tree/master/libraries/DHTstable
 //
@@ -18,7 +18,7 @@
 #include <Arduino.h>
 #endif
 
-#define DHT_LIB_VERSION "0.2.0 - dhtstable"
+#define DHT_LIB_VERSION "0.2.1 - dhtstable"
 
 #define DHTLIB_OK                0
 #define DHTLIB_ERROR_CHECKSUM   -1
diff --git a/libraries/DHTstable/library.properties b/libraries/DHTstable/library.properties
index f2c3cafc..560f6e07 100644
--- a/libraries/DHTstable/library.properties
+++ b/libraries/DHTstable/library.properties
@@ -1,5 +1,5 @@
 name=DHTStable
-version=0.2.0
+version=0.2.1
 author=Rob Tillaart <rob.tillaart@gmail.com>
 maintainer=Rob Tillaart <rob.tillaart@gmail.com>
 sentence=Stable version of library for DHT Temperature & Humidity Sensor 
diff --git a/libraries/DHTstable/readme.md b/libraries/DHTstable/readme.md
index b16e2873..6089d5ed 100644
--- a/libraries/DHTstable/readme.md
+++ b/libraries/DHTstable/readme.md
@@ -1,5 +1,5 @@
 
-This is the 0.2.0 version of the DHTlib. 
+This is the 0.2.1 version of the DHTlib. 
 This version is stable for both ARM and AVR.
 
 You can use most examples from https://github.com/RobTillaart/Arduino/tree/master/libraries/DHTlib/examples