diff --git a/README.md b/README.md
index d82a05521..56d7c4227 100644
--- a/README.md
+++ b/README.md
@@ -90,7 +90,7 @@ 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_0.5.226_amd64.deb
+sudo apt install build/meevax_0.5.227_amd64.deb
 ```
 
 or
@@ -122,9 +122,9 @@ sudo rm -rf /usr/local/share/meevax
 
 | Target Name | Description
 |-------------|-------------
-| `all`       | Build shared-library `libmeevax.0.5.226.so` and executable `meevax`
+| `all`       | Build shared-library `libmeevax.0.5.227.so` and executable `meevax`
 | `test`      | Test executable `meevax`
-| `package`   | Generate debian package `meevax_0.5.226_amd64.deb`
+| `package`   | Generate debian package `meevax_0.5.227_amd64.deb`
 | `install`   | Copy files into `/usr/local` directly
 
 ## Usage
diff --git a/VERSION b/VERSION
index d83bd7a3c..8098e54cc 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-0.5.226
+0.5.227
diff --git a/include/meevax/memory/collector.hpp b/include/meevax/memory/collector.hpp
index 370bf8448..68db795c9 100644
--- a/include/meevax/memory/collector.hpp
+++ b/include/meevax/memory/collector.hpp
@@ -17,11 +17,7 @@
 #ifndef INCLUDED_MEEVAX_MEMORY_COLLECTOR_HPP
 #define INCLUDED_MEEVAX_MEMORY_COLLECTOR_HPP
 
-#if __unix__
 #include <dlfcn.h> // dlopen, dlclose, dlerror
-#else
-#error
-#endif
 
 #include <memory> // std::allocator
 #include <unordered_map>