diff --git a/README.md b/README.md
index 53b658b..d442378 100644
--- a/README.md
+++ b/README.md
@@ -60,7 +60,7 @@ Usage
    
     $ bytes-circle -h   
    
-      circle v3.0 (goo.gl/TNh5dq)
+      circle v3.1 (goo.gl/TNh5dq)
 
     Show statistics about bytes contained in a file,
     as an ASCII circle graph of deviations from mean
diff --git a/circle.c b/circle.c
index 403b9ec..845f475 100644
--- a/circle.c
+++ b/circle.c
@@ -5,7 +5,7 @@
 // v1.2 by circulosmeos, 2016-01.
 // v2.1, v2.2 by circulosmeos, 2016-06.
 // v2.3 by circulosmeos, 2016-07.
-// v3.0 by circulosmeos, 2021-07.
+// v3.0, v3.1 by circulosmeos, 2021-07, 2021-08.
 // wp.me/p2FmmK-96
 // goo.gl/TNh5dq
 //
diff --git a/statistics.c b/statistics.c
index ad53e82..9502f50 100644
--- a/statistics.c
+++ b/statistics.c
@@ -7,7 +7,7 @@
 // v2.3 by circulosmeos, 2016-07.
 // v2.4, v2.5 by circulosmeos, 2016-12.
 // v2.6 by circulosmeos, 2018-12.
-// v3.0 by circulosmeos, 2021-07.
+// v3.0, v3.1 by circulosmeos, 2021-07, 2021-08.
 // wp.me/p2FmmK-96
 // goo.gl/TNh5dq
 //
diff --git a/statistics_circle.h b/statistics_circle.h
index ed9f9a6..8f7660a 100644
--- a/statistics_circle.h
+++ b/statistics_circle.h
@@ -6,7 +6,7 @@
 // v2.1, v2.2 by circulosmeos, 2016-06.
 // v2.3 by circulosmeos, 2016-07.
 // v2.4 by circulosmeos, 2016-12.
-// v3.0 by circulosmeos, 2021-07.
+// v3.0, v3.1 by circulosmeos, 2021-07, 2021-08.
 // wp.me/p2FmmK-96
 // goo.gl/TNh5dq
 //
@@ -55,7 +55,7 @@
 #endif
 
 #define PACKAGE_NAME    "circle"
-#define PACKAGE_STRING  "circle v3.0 (goo.gl/TNh5dq)"
+#define PACKAGE_STRING  "circle v3.1 (goo.gl/TNh5dq)"
 
 #define BUFFER_LENGTH 4096