diff --git a/llvm/core.py b/llvm/core.py
index 268318a..49b5561 100644
--- a/llvm/core.py
+++ b/llvm/core.py
@@ -28,10 +28,7 @@
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #
 
-try:
-    from cStringIO import StringIO
-except ImportError:
-    from StringIO import StringIO
+from io import BytesIO
 import contextlib, weakref
 
 import llvm
@@ -337,7 +334,7 @@ class Module(llvm.Wrapper):
             bc = fileobj_or_str
         else:
             bc = fileobj_or_str.read()
-        errbuf = StringIO()
+        errbuf = BytesIO()
         context = api.llvm.getGlobalContext()
         m = api.llvm.ParseBitCodeFile(bc, context, errbuf)
         if not m:
@@ -359,7 +356,7 @@ class Module(llvm.Wrapper):
             ir = fileobj_or_str
         else:
             ir = fileobj_or_str.read()
-        errbuf = StringIO()
+        errbuf = BytesIO()
         context = api.llvm.getGlobalContext()
         m = api.llvm.ParseAssemblyString(ir, None, api.llvm.SMDiagnostic.new(),
                                          context)
@@ -432,7 +429,7 @@ class Module(llvm.Wrapper):
         enum_mode = api.llvm.Linker.LinkerMode
         mode = enum_mode.PreserveSource if preserve else enum_mode.DestroySource
 
-        with contextlib.closing(StringIO()) as errmsg:
+        with contextlib.closing(BytesIO()) as errmsg:
             failed = api.llvm.Linker.LinkModules(self._ptr,
                                                  other._ptr,
                                                  mode,
@@ -512,7 +509,7 @@ class Module(llvm.Wrapper):
             Checks module for errors. Raises `llvm.LLVMException' on any
             error."""
         action = api.llvm.VerifierFailureAction.ReturnStatusAction
-        errio = StringIO()
+        errio = BytesIO()
         broken = api.llvm.verifyModule(self._ptr, action, errio)
         if broken:
             raise llvm.LLVMException(errio.getvalue())
@@ -530,7 +527,7 @@ class Module(llvm.Wrapper):
         ret = False
         if fileobj is None:
             ret = True
-            fileobj = StringIO
+            fileobj = BytesIO
         api.llvm.WriteBitcodeToFile(self._ptr, fileobj)
         if ret:
             return fileobj.getvalue()
@@ -571,7 +568,7 @@ class Module(llvm.Wrapper):
         ret = False
         if fileobj is None:
             ret = True
-            fileobj = StringIO()
+            fileobj = BytesIO()
         from llvm.ee import TargetMachine
         tm = TargetMachine.new()
         fileobj.write(tm.emit_object(self))
@@ -588,7 +585,7 @@ class Module(llvm.Wrapper):
         ret = False
         if fileobj is None:
             ret = True
-            fileobj = StringIO()
+            fileobj = BytesIO()
         from llvm.ee import TargetMachine
         tm = TargetMachine.new()
         fileobj.write(tm.emit_assembly(self))
@@ -2269,7 +2266,7 @@ def load_library_permanently(filename):
     Load the given shared library (filename argument specifies the full
     path of the .so file) using LLVM. Symbols from these are available
     from the execution engine thereafter."""
-    with contextlib.closing(StringIO()) as errmsg:
+    with contextlib.closing(BytesIO()) as errmsg:
         failed = api.llvm.sys.DynamicLibrary.LoadPermanentLibrary(filename,
                                                                   errmsg)
         if failed:
diff --git a/llvm/ee.py b/llvm/ee.py
index 8598ad9..030eacb 100644
--- a/llvm/ee.py
+++ b/llvm/ee.py
@@ -30,10 +30,7 @@
 
 "Execution Engine and related classes."
 
-try:
-    from cStringIO import StringIO
-except ImportError:
-    from StringIO import StringIO
+from io import BytesIO
 import contextlib
 
 import llvm
@@ -244,7 +241,7 @@ class TargetMachine(llvm.Wrapper):
             triple = get_default_triple()
         if not cpu:
             cpu = get_host_cpu_name()
-        with contextlib.closing(StringIO()) as error:
+        with contextlib.closing(BytesIO()) as error:
             target = api.llvm.TargetRegistry.lookupTarget(triple, error)
             if not target:
                 raise llvm.LLVMException(error)
@@ -273,7 +270,7 @@ class TargetMachine(llvm.Wrapper):
             use: `llvm-as < /dev/null | llc -march=xyz -mattr=help`
             '''
         triple = api.llvm.Triple.new()
-        with contextlib.closing(StringIO()) as error:
+        with contextlib.closing(BytesIO()) as error:
             target = api.llvm.TargetRegistry.lookupTarget(arch, triple, error)
             if not target:
                 raise llvm.LLVMException(error)
diff --git a/llvm/test_llvmpy.py b/llvm/test_llvmpy.py
index 5b26e39..8c9b800 100644
--- a/llvm/test_llvmpy.py
+++ b/llvm/test_llvmpy.py
@@ -10,13 +10,8 @@ import subprocess
 import tempfile
 import contextlib
 
-is_py3k = bool(sys.version_info[0] == 3)
 BITS = tuple.__itemsize__ * 8
-
-if is_py3k:
-    from io import StringIO
-else:
-    from cStringIO import StringIO
+from io import BytesIO
 
 
 import llvm
@@ -123,7 +118,7 @@ class TestAttr(TestCase):
                 ret void
             }
         """
-        return Module.from_assembly(StringIO(test_module))
+        return Module.from_assembly(BytesIO(test_module))
 
     def test_align(self):
         m = self.make_module()
@@ -255,7 +250,7 @@ entry:
 }
 """
     def test_operands(self):
-        m = Module.from_assembly(StringIO(self.test_module))
+        m = Module.from_assembly(BytesIO(self.test_module))
 
         test_func = m.get_function_named("test_func")
         prod = m.get_function_named("prod")
@@ -317,7 +312,7 @@ entry:
 }
 """
     def test_passes(self):
-        m = Module.from_assembly(StringIO(self.asm))
+        m = Module.from_assembly(BytesIO(self.asm))
 
         fn_test1 = m.get_function_named('test1')
         fn_test2 = m.get_function_named('test2')
@@ -365,7 +360,7 @@ entry:
         self.assertNotEqual(str(fn_test1).strip(), original_test1.strip())
 
     def test_passes_with_pmb(self):
-        m = Module.from_assembly(StringIO(self.asm))
+        m = Module.from_assembly(BytesIO(self.asm))
 
         fn_test1 = m.get_function_named('test1')
         fn_test2 = m.get_function_named('test2')