diff --git a/README.md b/README.md
index 409ef7a61..4b1ec45b6 100644
--- a/README.md
+++ b/README.md
@@ -105,9 +105,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name        | Description
 |:-------------------|:--
-| `all` (default)    | Build shared-library `libmeevax.0.4.208.so` and executable `meevax`.
+| `all` (default)    | Build shared-library `libmeevax.0.4.209.so` and executable `meevax`.
 | `test`             | Test executable `meevax`.
-| `package`          | Generate debian package `meevax_0.4.208_amd64.deb`.
+| `package`          | Generate debian package `meevax_0.4.209_amd64.deb`.
 | `install`          | Copy files into `/usr/local` __(1)__.
 | `install.deb`      | `all` + `package` + `sudo apt install <meevax>.deb`
 | `safe-install.deb` | `all` + `test` + `package` + `sudo apt install <meevax>.deb`
@@ -122,7 +122,7 @@ __(1)__ Meevax installed by `make install` cannot be uninstalled by the system's
 ## Usage
 
 ```
-Meevax Lisp System, version 0.4.208
+Meevax Lisp System, version 0.4.209
 
 Usage: meevax [OPTION...] [FILE...]
 
diff --git a/VERSION b/VERSION
index cab5b51e7..5e440409c 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.4.208
+0.4.209
diff --git a/include/meevax/memory/nan_boxing_pointer.hpp b/include/meevax/memory/nan_boxing_pointer.hpp
index cb795598b..36d24179f 100644
--- a/include/meevax/memory/nan_boxing_pointer.hpp
+++ b/include/meevax/memory/nan_boxing_pointer.hpp
@@ -229,7 +229,7 @@ inline namespace memory
         }
         else
         {
-          return os << yellow(value);
+          return os << std::fixed << std::setprecision(17) << yellow(value);
         }
       }
     }
diff --git a/test/nan_boxing_pointer.cpp b/test/nan_boxing_pointer.cpp
index f6d390856..b0369638e 100644
--- a/test/nan_boxing_pointer.cpp
+++ b/test/nan_boxing_pointer.cpp
@@ -125,7 +125,7 @@ auto main() -> int
   }
 
   {
-    assert(lexical_cast<external_representation>(make<double>(3.14)) == "3.14");
+    assert(lexical_cast<external_representation>(make<double>(3.14)) == "3.14000000000000012");
     assert(lexical_cast<external_representation>(make<std::int32_t>(42)) == "42");
   }