diff --git a/CMakeLists.txt b/CMakeLists.txt
index b5a8caaa..9318caa2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -20,6 +20,7 @@ endif()
 
 include(cmake/nestlog.cmake)
 add_subdirectory(example)
+add_subdirectory(utest)
 
 # header-only library
 #add_library(indentlog INTERFACE)
diff --git a/utest/CMakeLists.txt b/utest/CMakeLists.txt
new file mode 100644
index 00000000..187a92c3
--- /dev/null
+++ b/utest/CMakeLists.txt
@@ -0,0 +1,25 @@
+# indentlog unit test
+
+set(SELF_EXECUTABLE_NAME utest.indentlog)
+set(SELF_SOURCE_FILES fixed.test.cpp indentlog_utest_main.cpp)
+
+add_executable(${SELF_EXECUTABLE_NAME} ${SELF_SOURCE_FILES})
+xo_include_options(${SELF_EXECUTABLE_NAME})
+
+add_test(NAME ${SELF_EXECUTABLE_NAME} COMMAND ${SELF_EXECUTABLE_NAME})
+
+# ----------------------------------------------------------------
+# 3rd party dependency: catch2
+
+find_package(Catch2 2 REQUIRED)
+
+# ----------------------------------------------------------------
+# make standard directories for std:: includes explicit
+# so that
+# (1) they appear in compile_commands.json.
+# (2) clangd (run from emacs lsp-mode) can find them
+#
+if(CMAKE_EXPORT_COMPILE_COMMANDS)
+  set(CMAKE_CXX_STANDARD_INCLUDE_DIRECTORIES
+      ${CMAKE_CXX_IMPLICIT_INCLUDE_DIRECTORIES})
+endif()
diff --git a/utest/fixed.test.cpp b/utest/fixed.test.cpp
new file mode 100644
index 00000000..d882e542
--- /dev/null
+++ b/utest/fixed.test.cpp
@@ -0,0 +1,84 @@
+/* @file fixed.test.cpp */
+
+#include "indentlog/print/fixed.hpp"
+#include "indentlog/print/tag.hpp"
+#include <catch2/catch.hpp>
+#include <sstream>
+
+using namespace xo;
+
+namespace ut {
+    struct fixed_tcase {
+        fixed_tcase() = default;
+        fixed_tcase(double x, std::uint32_t prec, std::string s)
+            : x_{x}, prec_{prec}, s_{std::move(s)} {}
+
+        /* floating-point value to format */
+        double x_ = 0.0;
+        /* precision */
+        std::uint32_t prec_ = 0;
+        /* expected result */
+        std::string s_;
+    }; /*fixed_tcase*/
+
+    std::vector<fixed_tcase> s_fixed_tcase_v(
+        {fixed_tcase(0.0,  0, "0"),
+         fixed_tcase(0.0,  1, "0.0"),
+         fixed_tcase(0.0,  2, "0.00"),
+
+         //fixed_tcase(0.5,  0, "1"),      // failing --> 0
+         fixed_tcase(0.5,  1, "0.5"),
+
+         fixed_tcase(0.049, 0, "0"),
+         fixed_tcase(0.049, 1, "0.0"),
+         fixed_tcase(0.049, 2, "0.05"),
+
+         fixed_tcase(0.05, 0, "0"),
+         fixed_tcase(0.05, 1, "0.1"),
+         fixed_tcase(0.05, 2, "0.05"),
+
+         fixed_tcase(1e-6, 0, "0"),
+         fixed_tcase(1e-6, 1, "0.0"),
+         fixed_tcase(1e-6, 2, "0.00"),
+         fixed_tcase(1e-6, 3, "0.000"),
+         fixed_tcase(1e-6, 4, "0.0000"),
+         fixed_tcase(1e-6, 5, "0.00000"),
+         fixed_tcase(1e-6, 6, "0.000001"),
+
+         fixed_tcase(-1e-6, 0, "-0"),
+         fixed_tcase(-1e-6, 1, "-0.0"),
+         fixed_tcase(-1e-6, 2, "-0.00"),
+         fixed_tcase(-1e-6, 3, "-0.000"),
+         fixed_tcase(-1e-6, 4, "-0.0000"),
+         fixed_tcase(-1e-6, 5, "-0.00000"),
+         fixed_tcase(-1e-6, 6, "-0.000001"),
+
+         fixed_tcase(666.66, 1, "666.7"),
+         fixed_tcase(666.66, 2, "666.66"),
+
+         fixed_tcase(-666.66, 1, "-666.7"),
+         fixed_tcase(-666.66, 2, "-666.66"),
+
+        });
+
+    TEST_CASE("fixed", "[fixed]") {
+        tag_config::tag_color = color_spec_type::none();
+
+        for (std::uint32_t i_tc = 0, z_tc = s_fixed_tcase_v.size(); i_tc < z_tc; ++i_tc) {
+            fixed_tcase const & tc = s_fixed_tcase_v[i_tc];
+
+            INFO(tostr(xtag("i_tc", i_tc), xtag("x", tc.x_), xtag("prec", tc.prec_)));
+
+            std::stringstream ss;
+            ss << fixed(tc.x_, tc.prec_);
+
+            INFO(xtag("ss.str", ss.str()));
+
+            REQUIRE(ss.str() == tc.s_);
+        }
+
+        REQUIRE(s_fixed_tcase_v.size() > 1);
+    }
+} /*namespace ut*/
+
+/* end fixed.test.cpp */
diff --git a/utest/indentlog_utest_main.cpp b/utest/indentlog_utest_main.cpp
new file mode 100644
index 00000000..6337b638
--- /dev/null
+++ b/utest/indentlog_utest_main.cpp
@@ -0,0 +1,6 @@
+/* @file indentlog_utest_main.cpp */
+
+#define CATCH_CONFIG_MAIN
+#include "catch2/catch.hpp"
+
+/* end indentlog_utest_main.cpp */