diff --git a/ChangeLog b/ChangeLog
index a7777719..10e5eebe 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,9 @@
+2014-11-23  Joerg Wunsch <j.gnu@uriah.heep.sax.de>
+
+	bug #40870: config nitpick: ATtiny25/45/85 have 1 calibration byte not 2
+	* avrdude.conf.in (ATtiny25, ATtiny45, ATtiny85): Fix size of
+	"calibration" memory area
+
 2014-11-23  Joerg Wunsch <j.gnu@uriah.heep.sax.de>
 
 	bug #43137: Writing and reading incorrect pages when using jtagicemkI
diff --git a/NEWS b/NEWS
index c5f55613..ecf411a1 100644
--- a/NEWS
+++ b/NEWS
@@ -28,6 +28,7 @@ Current:
                   flash page
     - bug #43078: AVRDUDE crashes after sucessfully reading/writing eeprom
     - bug #43137: Writing and reading incorrect pages when using jtagicemkI
+    - bug #40870: config nitpick: ATtiny25/45/85 have 1 calibration byte not 2
 
   * Internals:
     - ...
diff --git a/avrdude.conf.in b/avrdude.conf.in
index 52d87dc9..c91a2534 100644
--- a/avrdude.conf.in
+++ b/avrdude.conf.in
@@ -9407,7 +9407,7 @@ part
      ;
 
      memory "calibration"
-         size            = 2;
+         size            = 1;
          read            = "0  0  1  1   1  0  0  0    0 0 0 x  x x x x",
                            "0  0  0  0   0  0  0  a0   o o o o  o o o o";
      ;
@@ -9588,7 +9588,7 @@ part
      ;
 
      memory "calibration"
-         size            = 2;
+         size            = 1;
          read            = "0  0  1  1   1  0  0  0    0 0 0 x  x x x x",
                            "0  0  0  0   0  0  0  a0   o o o o  o o o o";
      ;
@@ -9770,7 +9770,7 @@ part
      ;
 
      memory "calibration"
-         size            = 2;
+         size            = 1;
          read            = "0  0  1  1   1  0  0  0    0 0 0 x  x x x x",
                            "0  0  0  0   0  0  0  a0   o o o o  o o o o";
      ;