diff --git a/pyfastani/_sequtils/sequtils.cpp b/pyfastani/_sequtils/sequtils.cpp
index 1946c0c..30d3439 100644
--- a/pyfastani/_sequtils/sequtils.cpp
+++ b/pyfastani/_sequtils/sequtils.cpp
@@ -14,11 +14,6 @@ static const X86Features features = GetX86Info().features;
 using namespace cpu_features;
 static const ArmFeatures features = GetArmInfo().features;
 #endif
-#ifdef __aarch64__
-#include "cpuinfo_aarch64.h"
-using namespace cpu_features;
-static const Aarch64Features features = GetAarch64Info().features;
-#endif
 
 extern "C" {
     // --- Fast copy with uppercase --------------------------------------------
@@ -49,17 +44,20 @@ extern "C" {
         #endif
         #ifdef __aarch64__
         #ifdef NEON_BUILD_SUPPORTED
-          if (features.neon)
-            return neon_copy_upper(dst, src, len);
-          else
+          return neon_copy_upper(dst, src, len);
         #endif
         #endif
-        #if defined(__x86__) || defined(__x86_64__)
+        #ifdef __x86__
         #ifdef SSE2_BUILD_SUPPORTED
           if (features.sse2)
-            return sse2_copy_upper(dst, src, len); // fast copying plus upper.
+            return sse2_copy_upper(dst, src, len);
           else
         #endif
+        #endif
+        #ifdef __x86_64__
+        #ifdef SSE2_BUILD_SUPPORTED
+          return sse2_copy_upper(dst, src, len);
+        #endif
         #endif
             return default_copy_upper(dst, src, len);
     }
diff --git a/setup.cfg b/setup.cfg
index 2754d6b..8d6d22b 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -28,12 +28,14 @@ classifier =
     Programming Language :: Python :: 3.9
     Programming Language :: Python :: 3.10
     Programming Language :: Python :: 3.11
+    Programming Language :: Python :: 3.12
     Programming Language :: Python :: Implementation :: CPython
     Programming Language :: Python :: Implementation :: PyPy
     Topic :: Scientific/Engineering :: Bio-Informatics
     Topic :: Scientific/Engineering :: Medical Science Apps.
     Typing :: Typed
 project_urls =
+    Documentation = https://pyfastani.readthedocs.io/en/stable/
     Bug Tracker = https://github.com/althonos/pyfastani/issues
     Changelog = https://github.com/althonos/pyfastani/blob/master/CHANGELOG.md
     Coverage = https://codecov.io/gh/althonos/pyfastani/
diff --git a/setup.py b/setup.py
index 2e1226d..ac09f7a 100644
--- a/setup.py
+++ b/setup.py
@@ -351,7 +351,6 @@ def _check_getid(self):
             flags = ["-Werror=implicit-function-declaration"]
 
         try:
-            self.mkpath(self.build_temp)
             objects = self.compiler.compile([testfile], extra_postargs=flags)
         except CompileError:
             _eprint("no")
@@ -426,6 +425,11 @@ def build_extensions(self):
         # remove universal compilation flags for OSX
         if PLATFORM_SYSTEM == "Darwin":
             _patch_osx_compiler(self.compiler)
+
+        # check if `PyInterpreterState_GetID` is available
+        if self._check_getid():
+            self.compiler.define_macro("HAS_PYINTERPRETERSTATE_GETID", 1)
+
         # build the extensions as normal
         _build_ext.build_extensions(self)
 
@@ -443,10 +447,6 @@ def build_extension(self, ext):
         else:
             ext.define_macros.append(("CYTHON_WITHOUT_ASSERTIONS", 1))
 
-        # check if `PyInterpreterState_GetID` is available
-        if self._check_getid():
-            ext.define_macros.append(("HAS_PYINTERPRETERSTATE_GETID", 1))
-
         # C++ OS-specific options
         if ext.language == "c++":
             # make sure to build with C++11