diff --git a/bindings/ruby/unicorn_gem/ext/unicorn.h b/bindings/ruby/unicorn_gem/ext/unicorn.h
index 30b417d9..05fb2608 100644
--- a/bindings/ruby/unicorn_gem/ext/unicorn.h
+++ b/bindings/ruby/unicorn_gem/ext/unicorn.h
@@ -26,7 +26,6 @@ VALUE m_uc_reg_write(VALUE self, VALUE reg_id, VALUE reg_value);
 VALUE m_uc_mem_read(VALUE self, VALUE address, VALUE size);
 VALUE m_uc_mem_write(VALUE self, VALUE address, VALUE bytes);
 VALUE m_uc_mem_map(int argc, VALUE* argv, VALUE self);
-//VALUE m_uc_mem_map_ptr(VALUE self, VALUE address, VALUE size, VALUE perms, VALUE ptr);
 VALUE m_uc_mem_unmap(VALUE self, VALUE address, VALUE size);
 VALUE m_uc_mem_protect(VALUE self, VALUE address, VALUE size, VALUE perms);
 VALUE m_uc_hook_add(int argc, VALUE* argv, VALUE self);
diff --git a/tests/regress/x86_gdt.py b/tests/regress/x86_gdt.py
new file mode 100644
index 00000000..3565a74c
--- /dev/null
+++ b/tests/regress/x86_gdt.py
@@ -0,0 +1,94 @@
+#!/usr/bin/env python
+from unicorn import *
+from unicorn.x86_const import *
+from struct import pack
+
+import regress
+
+F_GRANULARITY = 0x8
+F_PROT_32 = 0x4
+F_LONG = 0x2
+F_AVAILABLE = 0x1 
+
+A_PRESENT = 0x80
+
+A_PRIV_3 = 0x60
+A_PRIV_2 = 0x40
+A_PRIV_1 = 0x20
+A_PRIV_0 = 0x0
+
+A_CODE = 0x10
+A_DATA = 0x10
+A_TSS = 0x0
+A_GATE = 0x0
+
+A_DATA_WRITABLE = 0x2
+A_CODE_READABLE = 0x2
+
+A_DIR_CON_BIT = 0x4
+
+S_GDT = 0x0
+S_LDT = 0x4
+S_PRIV_3 = 0x3
+S_PRIV_2 = 0x2
+S_PRIV_1 = 0x1
+S_PRIV_0 = 0x0
+
+CODE = '65330d18000000'.decode('hex') # xor ecx, dword ptr gs:[0x18]
+
+def create_selector(idx, flags):
+    to_ret = flags
+    to_ret |= idx << 3
+    return to_ret
+
+def create_gdt_entry(base, limit, access, flags):
+
+    to_ret = limit & 0xffff;
+    to_ret |= (base & 0xffffff) << 16;
+    to_ret |= (access & 0xff) << 40;
+    to_ret |= ((limit >> 16) & 0xf) << 48;
+    to_ret |= (flags & 0xff) << 52;
+    to_ret |= ((base >> 24) & 0xff) << 56;
+    return pack('<Q',to_ret)
+
+def hook_mem_read(uc, type, addr,*args):
+    print(hex(addr))
+    return False
+
+CODE_ADDR = 0x40000
+CODE_SIZE = 0x1000
+
+GDT_ADDR = 0x3000
+GDT_LIMIT = 0x1000
+GDT_ENTRY_SIZE = 0x8
+
+SEGMENT_ADDR = 0x5000
+SEGMENT_SIZE = 0x1000
+
+class GdtRead(regress.RegressTest):
+
+    def test_gdt(self):
+        uc = Uc(UC_ARCH_X86, UC_MODE_32)
+        uc.hook_add(UC_HOOK_MEM_READ_UNMAPPED, hook_mem_read)
+
+        uc.mem_map(GDT_ADDR, GDT_LIMIT)
+        uc.mem_map(SEGMENT_ADDR, SEGMENT_SIZE)
+        uc.mem_map(CODE_ADDR, CODE_SIZE)
+
+        uc.mem_write(CODE_ADDR, CODE)
+        uc.mem_write(SEGMENT_ADDR+0x18, 'AAAA')
+
+        gdt_entry = create_gdt_entry(SEGMENT_ADDR, SEGMENT_SIZE, A_PRESENT | A_DATA | A_DATA_WRITABLE | A_PRIV_3 | A_DIR_CON_BIT, F_PROT_32)
+        uc.mem_write(GDT_ADDR + 8, gdt_entry)
+
+        uc.reg_write(UC_X86_REG_GDTR, (0, GDT_ADDR, GDT_LIMIT, 0x0))
+
+        selector = create_selector(1, S_GDT | S_PRIV_3)
+        uc.reg_write(UC_X86_REG_GS, selector)
+
+        uc.emu_start(CODE_ADDR, CODE_ADDR+len(CODE))
+
+        self.assertEqual(uc.read_reg(UC_X86_REG_ECX), 0x41414141)
+
+if __name__ == '__main__':
+    regress.main()
\ No newline at end of file