diff --git a/README.md b/README.md
index 4ce32d5c1..0c9062f34 100644
--- a/README.md
+++ b/README.md
@@ -91,7 +91,7 @@ Procedures for each standard are provided by the following R7RS-style libraries:
 cmake -B build -DCMAKE_BUILD_TYPE=Release
 cd build
 make package
-sudo apt install build/meevax_0.5.83_amd64.deb
+sudo apt install build/meevax_0.5.84_amd64.deb
 ```
 
 or
@@ -123,9 +123,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.83.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.84.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.83_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.84_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index cacdd2d09..05a42e401 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.83
+0.5.84
diff --git a/include/meevax/memory/bit_cast.hpp b/include/meevax/bit/bit_cast.hpp
similarity index 86%
rename from include/meevax/memory/bit_cast.hpp
rename to include/meevax/bit/bit_cast.hpp
index fcc4145be..352214aa3 100644
--- a/include/meevax/memory/bit_cast.hpp
+++ b/include/meevax/bit/bit_cast.hpp
@@ -14,8 +14,8 @@
    limitations under the License.
 */
 
-#ifndef INCLUDED_MEEVAX_MEMORY_BIT_CAST_HPP
-#define INCLUDED_MEEVAX_MEMORY_BIT_CAST_HPP
+#ifndef INCLUDED_MEEVAX_BIT_BIT_CAST_HPP
+#define INCLUDED_MEEVAX_BIT_BIT_CAST_HPP
 
 #include <cstring>
 
@@ -23,7 +23,7 @@
 
 namespace meevax
 {
-inline namespace memory
+inline namespace bit
 {
   template <typename To,
             typename From,
@@ -37,7 +37,7 @@ inline namespace memory
     std::memcpy(&to, &from, sizeof from);
     return to;
   }
-} // namespace memory
+} // namespace bit
 } // namespace meevax
 
-#endif // INCLUDED_MEEVAX_MEMORY_BIT_CAST_HPP
+#endif // INCLUDED_MEEVAX_BIT_BIT_CAST_HPP
diff --git a/include/meevax/memory/nan_boxing_pointer.hpp b/include/meevax/memory/nan_boxing_pointer.hpp
index 437e40f40..9fad8ceba 100644
--- a/include/meevax/memory/nan_boxing_pointer.hpp
+++ b/include/meevax/memory/nan_boxing_pointer.hpp
@@ -23,7 +23,7 @@
 #include <ostream>
 #include <typeinfo>
 
-#include <meevax/memory/bit_cast.hpp>
+#include <meevax/bit/bit_cast.hpp>
 #include <meevax/type_traits/integer.hpp>
 
 namespace meevax
diff --git a/include/meevax/memory/tagged_pointer.hpp b/include/meevax/memory/tagged_pointer.hpp
index ba6f9cb7b..a0c43156c 100644
--- a/include/meevax/memory/tagged_pointer.hpp
+++ b/include/meevax/memory/tagged_pointer.hpp
@@ -19,7 +19,7 @@
 
 #include <stdexcept>
 
-#include <meevax/memory/bit_cast.hpp>
+#include <meevax/bit/bit_cast.hpp>
 #include <meevax/memory/simple_pointer.hpp>
 #include <meevax/type_traits/integer.hpp>