diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index c306b27..49b02c4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -42,6 +42,15 @@ jobs:
       - name: Check header is up to date
         run: ./tools/is_header_up_to_date.sh
 
+  version-updated:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Check version is up to date
+        run: ./tools/check_version.sh
+
   posix-coverage:
     runs-on: ubuntu-latest
     steps:
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8bd7c75..d277675 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -3,8 +3,6 @@ cmake_minimum_required(VERSION 3.10)
 # CMake fix for crosscompile (MinGW-w64)
 set(CMAKE_TRY_COMPILE_TARGET_TYPE "STATIC_LIBRARY")
 
-project(tinycsocket VERSION 0.4)
-
 include(CheckSymbolExists)
 include(CheckIncludeFile)
 
@@ -69,6 +67,15 @@ set(TINYCSOCKET_SRC
     "src/tinycsocket_posix.c"
 )
 
+# Version generation
+add_custom_target(
+    generate_version
+    COMMAND ${CMAKE_COMMAND} -DSRC_DIR=${CMAKE_CURRENT_SOURCE_DIR}
+        -P ${CMAKE_CURRENT_SOURCE_DIR}/cmake/GenerateVersion.cmake
+    WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
+)
+set_target_properties(generate_version PROPERTIES FOLDER tinycsocket)
+
 # Header generation
 add_custom_command(
     OUTPUT ${CMAKE_CURRENT_SOURCE_DIR}/include/tinycsocket.h
@@ -81,6 +88,7 @@ add_custom_command(
 add_custom_target(
     generate_header
     SOURCES ${CMAKE_CURRENT_SOURCE_DIR}/include/tinycsocket.h
+    DEPENDS generate_version
 )
 set_target_properties(generate_header PROPERTIES FOLDER tinycsocket)
 
@@ -110,9 +118,6 @@ if(TCS_WARNINGS_AS_ERRORS)
     endif()
 endif()
 
-install(TARGETS tinycsocket DESTINATION lib)
-install(FILES include/tinycsocket.h DESTINATION include)
-
 # Extra targets for development
 if(TCS_ENABLE_TESTS)
     enable_testing()
diff --git a/cmake/GenerateVersion.cmake b/cmake/GenerateVersion.cmake
new file mode 100644
index 0000000..bfce476
--- /dev/null
+++ b/cmake/GenerateVersion.cmake
@@ -0,0 +1,63 @@
+# Generates TCS_VERSION_TXT from git tag + first-parent commit count.
+# Format: {tag}.{count}
+
+find_package(Git QUIET)
+if(NOT GIT_FOUND)
+    message(WARNING "Git not found, skipping version generation")
+    return()
+endif()
+
+# Get latest tag
+execute_process(
+    COMMAND "${GIT_EXECUTABLE}" describe --tags --abbrev=0
+    WORKING_DIRECTORY "${SRC_DIR}"
+    RESULT_VARIABLE res
+    OUTPUT_VARIABLE tag
+    ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+if(NOT res EQUAL 0)
+    message(WARNING "No git tags found, skipping version generation")
+    return()
+endif()
+
+# Count first-parent commits on master since tag
+execute_process(
+    COMMAND "${GIT_EXECUTABLE}" rev-list --count --first-parent "${tag}..origin/master"
+    WORKING_DIRECTORY "${SRC_DIR}"
+    RESULT_VARIABLE res
+    OUTPUT_VARIABLE count
+    ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+if(NOT res EQUAL 0)
+    set(count "0")
+endif()
+
+# If not on master, add 1 to anticipate the merge commit
+execute_process(
+    COMMAND "${GIT_EXECUTABLE}" rev-parse --abbrev-ref HEAD
+    WORKING_DIRECTORY "${SRC_DIR}"
+    RESULT_VARIABLE res
+    OUTPUT_VARIABLE branch
+    ERROR_QUIET OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+if(NOT "${branch}" STREQUAL "master")
+    math(EXPR count "${count} + 1")
+endif()
+
+set(version "${tag}.${count}")
+
+# Update header
+set(HEADER_FILE "${SRC_DIR}/src/tinycsocket_internal.h")
+file(READ "${HEADER_FILE}" content)
+
+string(REGEX REPLACE
+    "(static const char\\* const TCS_VERSION_TXT = \")[^\"]*(\")"
+    "\\1${version}\\2"
+    new_content "${content}")
+
+if(NOT "${content}" STREQUAL "${new_content}")
+    file(WRITE "${HEADER_FILE}" "${new_content}")
+    message(STATUS "Updated TCS_VERSION_TXT to \"${version}\"")
+else()
+    message(STATUS "TCS_VERSION_TXT already \"${version}\"")
+endif()
diff --git a/include/tinycsocket.h b/include/tinycsocket.h
index 228075e..fa2aaeb 100644
--- a/include/tinycsocket.h
+++ b/include/tinycsocket.h
@@ -35,7 +35,7 @@
 
 #define tcs_static_assert(name, expr) typedef char tcs_sa_##name[(expr) ? 1 : -1]
 
-static const char* const TCS_VERSION_TXT = "v0.4-dev";
+static const char* const TCS_VERSION_TXT = "v0.3.56";
 static const char* const TCS_LICENSE_TXT =
     "Copyright 2018 Markus Lindelöw\n"
     "\n"
diff --git a/src/tinycsocket_internal.h b/src/tinycsocket_internal.h
index 50cc582..b21bf6f 100644
--- a/src/tinycsocket_internal.h
+++ b/src/tinycsocket_internal.h
@@ -29,7 +29,7 @@
 
 #define tcs_static_assert(name, expr) typedef char tcs_sa_##name[(expr) ? 1 : -1]
 
-static const char* const TCS_VERSION_TXT = "v0.4-dev";
+static const char* const TCS_VERSION_TXT = "v0.3.56";
 static const char* const TCS_LICENSE_TXT =
     "Copyright 2018 Markus Lindelöw\n"
     "\n"
diff --git a/tools/check_version.sh b/tools/check_version.sh
new file mode 100755
index 0000000..b186c38
--- /dev/null
+++ b/tools/check_version.sh
@@ -0,0 +1,22 @@
+#!/bin/sh
+# Verifies TCS_VERSION_TXT matches git. Format: <tag>.<first-parent count>
+set -e
+
+PROJPATH="$(dirname "$(readlink -f "$0")")"/..
+TAG=$(git -C "$PROJPATH" describe --tags --abbrev=0)
+ACTUAL=$(grep 'const TCS_VERSION_TXT =' "$PROJPATH/src/tinycsocket_internal.h" | sed 's/.*"\(.*\)".*/\1/')
+
+if [ "${GITHUB_REF:-}" = "refs/heads/master" ]; then
+    COUNT=$(git -C "$PROJPATH" rev-list --count --first-parent "$TAG..HEAD")
+else
+    COUNT=$(( $(git -C "$PROJPATH" rev-list --count --first-parent "$TAG..origin/master") + 1 ))
+fi
+
+EXPECTED="${TAG}.${COUNT}"
+
+if [ "$ACTUAL" != "$EXPECTED" ]; then
+    echo "Version mismatch: header has \"$ACTUAL\", expected \"$EXPECTED\""
+    exit 1
+fi
+
+echo "Version OK: $ACTUAL"