diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7835ae3..73b0a26 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,12 @@
 This is the changelog for `cxxopts`, a C++11 library for parsing command line
 options. The project adheres to semantic versioning.
 
+## 3.1.1
+
+### Bug Fixes
+
+* Fixed version number in header.
+
 ## 3.1
 
 ### Added
diff --git a/include/cxxopts.hpp b/include/cxxopts.hpp
index e39ca51..b789a5c 100644
--- a/include/cxxopts.hpp
+++ b/include/cxxopts.hpp
@@ -84,8 +84,8 @@ THE SOFTWARE.
 #endif
 
 #define CXXOPTS__VERSION_MAJOR 3
-#define CXXOPTS__VERSION_MINOR 0
-#define CXXOPTS__VERSION_PATCH 0
+#define CXXOPTS__VERSION_MINOR 1
+#define CXXOPTS__VERSION_PATCH 1
 
 #if (__GNUC__ < 10 || (__GNUC__ == 10 && __GNUC_MINOR__ < 1)) && __GNUC__ >= 6
   #define CXXOPTS_NULL_DEREF_IGNORE