diff --git a/binding/miniffi-binding.cpp b/binding/miniffi-binding.cpp
index 60c4d8f7..0b6fbe77 100644
--- a/binding/miniffi-binding.cpp
+++ b/binding/miniffi-binding.cpp
@@ -97,7 +97,6 @@ RB_METHOD(MiniFFI_initialize) {
   rb_iv_set(self, "_func", MVAL2RB((mffi_value)hfunc));
   rb_iv_set(self, "_funcname", func);
   rb_iv_set(self, "_libname", libname);
-  rb_iv_set(self, "_64bit", rb_bool_new(libIs64(RSTRING_PTR(func))));
 
   VALUE ary_imports = rb_ary_new();
   VALUE *entry;
diff --git a/binding/miniffi.cpp b/binding/miniffi.cpp
index 1df64c43..401c059e 100644
--- a/binding/miniffi.cpp
+++ b/binding/miniffi.cpp
@@ -2,49 +2,37 @@
 #include <assert.h>
 
 #if defined(__linux__) || defined(__APPLE__)
-mffi_value miniffi_call_intern(MINIFFI_FUNC target, MiniFFIFuncArgs *p, int nparams, bool is64) {
+mffi_value miniffi_call_intern(MINIFFI_FUNC target, MiniFFIFuncArgs *p, int nparams) {
     assert(nparams <= 8);
     return target(p->params[0], p->params[1], p->params[2], p->params[3],
                                  p->params[4], p->params[5], p->params[6], p->params[7]);
 }
-// It does not actually matter whether the library is 64-bit or not,
-// on Linux and macOS we only load the same architecture
-// In the future this will probably only check so that it's possible
-// to raise an error
-bool libIs64(void *handle) {
-    return true;
-}
 #else
-#include <windows.h>
-mffi_value miniffi_call_intern(MINIFFI_FUNC target, MiniFFIFuncArgs *p, int nparams, bool is64) {
-#ifdef __MINGW64__
-    if (is64)
-        return call_asm64(target, p, nparams);
-    return call_asm32(target, p, nparams);
-}
 #define INTEL_ASM ".intel_syntax noprefix\n"
 __attribute__((noinline))
-mffi_value call_asm32(MINIFFI_FUNC target, MiniFFIFuncArgs *p, int nparams) {
+#ifndef __MINGW64__
+mffi_value miniffi_call_intern(MINIFFI_FUNC target, MiniFFIFuncArgs *p, int nparams) {
     mffi_value ret;
     void *old_esp = 0;
 
     asm volatile(INTEL_ASM
 
+                "MiniFFI_call_asm:\n"
                 "mov [edi], esp\n"
                 "test ebx, ebx\n"
-                "jz mffi_call_void32\n"
+                "jz mffi_call_void\n"
                 
                 "shl ebx, 2\n"
                 "mov ecx, ebx\n"
                 
-                "mffi_call_loop32:\n"
+                "mffi_call_loop:\n"
                 "sub ecx, 4\n"
                 "mov ebx, [esi+ecx]\n"
                 "push ebx\n"
                 "test ecx, ecx\n"
-                "jnz mffi_call_loop32\n"
+                "jnz mffi_call_loop\n"
                 
-                "mffi_call_void32:\n"
+                "mffi_call_void:\n"
                 "call edx\n"
                 
                 : "=a"(ret)
@@ -65,28 +53,28 @@ mffi_value call_asm32(MINIFFI_FUNC target, MiniFFIFuncArgs *p, int nparams) {
     );
     return ret;
 }
-#ifdef __MINGW64__
-__attribute__((noinline))
-mffi_value call_asm64(MINIFFI_FUNC target, MiniFFIFuncArgs *p, int nparams) {
+#else
+mffi_value miniffi_call_intern(MINIFFI_FUNC target, MiniFFIFuncArgs *p, int nparams) {
     mffi_value ret;
     void *old_rsp = 0;
     asm volatile(INTEL_ASM
 
+                "MiniFFI_call_asm:\n"
                 "mov [rdi], rsp\n"
                 "test rbx, rbx\n"
-                "jz mffi_call_void64\n"
+                "jz mffi_call_void\n"
                 
                 "shl rbx, 2\n"
                 "mov rcx, rbx\n"
                 
-                "mffi_call_loop64:\n"
+                "mffi_call_loop:\n"
                 "sub rcx, 4\n"
                 "mov rbx, [rsi+rcx]\n"
                 "push rbx\n"
                 "test rcx, rcx\n"
-                "jnz mffi_call_loop64\n"
+                "jnz mffi_call_loop\n"
                 
-                "mffi_call_void64:\n"
+                "mffi_call_void:\n"
                 "call rdx\n"
                 
                 : "=a"(ret)
@@ -104,17 +92,4 @@ mffi_value call_asm64(MINIFFI_FUNC target, MiniFFIFuncArgs *p, int nparams) {
     return ret;
 }
 #endif
-
-bool libIs64(const char *lib) {
-    LOADED_IMAGE *img = ImageLoad(lib, NULL);
-
-    // Just assume 32-bit for now
-    if (!img)
-        return false;
-        
-    IMAGE_NT_HEADERS *imgheaders = img->FileHeader;
-    bool ret = imgheaders->FileHeader->Machine != IMAGE_FILE_MACHINE_I386;
-    ImageUnload(img);
-    return ret;
-}
 #endif
diff --git a/binding/miniffi.h b/binding/miniffi.h
index c9ff8f81..995def44 100644
--- a/binding/miniffi.h
+++ b/binding/miniffi.h
@@ -23,6 +23,4 @@ typedef struct {
   mffi_value params[MINIFFI_MAX_ARGS];
 } MiniFFIFuncArgs;
 
-mffi_value miniffi_call_intern(MINIFFI_FUNC target, MiniFFIFuncArgs *p, int nparams, bool is64);
-
-bool libIs64(void *handle);
\ No newline at end of file
+mffi_value miniffi_call_intern(MINIFFI_FUNC target, MiniFFIFuncArgs *p, int nparams);