diff --git a/bin/vyper b/bin/vyper
index d2e470bb943..15ad6aa49d3 100755
--- a/bin/vyper
+++ b/bin/vyper
@@ -158,7 +158,6 @@ if __name__ == '__main__':
         out = vyper.compile_codes(
             codes,
             ['bytecode', 'bytecode_runtime', 'abi', 'source_map', 'method_identifiers'],
-            output_type='dict',
             exc_handler=exc_handler,
             interface_codes=get_interface_codes(codes)
         )
@@ -177,13 +176,12 @@ if __name__ == '__main__':
         for f in orig_args:
             formats.append(translate_map.get(f, f))
 
-        out_list = vyper.compile_codes(
+        out_list = list(vyper.compile_codes(
             codes,
             formats,
-            output_type='list',
             exc_handler=exc_handler,
             interface_codes=get_interface_codes(codes)
-        )
+        ).values())
 
         for out in out_list:
             for f in orig_args:
diff --git a/bin/vyper-serve b/bin/vyper-serve
index c89968bcc54..0d7b1f4871a 100755
--- a/bin/vyper-serve
+++ b/bin/vyper-serve
@@ -92,7 +92,6 @@ class VyperRequestHandler(BaseHTTPRequestHandler):
             out_dict = vyper.compile_codes(
                 {'': code},
                 vyper.compiler.output_formats_map.keys(),
-                output_type='dict',
             )['']
             out_dict['ir'] = str(out_dict['ir'])
         except ParserException as e:
diff --git a/tests/compiler/test_bytecode_runtime.py b/tests/compiler/test_bytecode_runtime.py
index b9754d2f6de..90e603b9ff4 100644
--- a/tests/compiler/test_bytecode_runtime.py
+++ b/tests/compiler/test_bytecode_runtime.py
@@ -8,7 +8,7 @@ def a() -> bool:
     return True
     """
 
-    out = vyper.compile_codes({'': code}, ['bytecode_runtime', 'bytecode'])[0]
+    out = vyper.compile_code(code, ['bytecode_runtime', 'bytecode'])
 
     assert len(out['bytecode']) > len(out['bytecode_runtime'])
     assert out['bytecode_runtime'][2:] in out['bytecode'][2:]
diff --git a/tests/compiler/test_opcodes.py b/tests/compiler/test_opcodes.py
index c9fcf427e01..5248718dd78 100644
--- a/tests/compiler/test_opcodes.py
+++ b/tests/compiler/test_opcodes.py
@@ -8,7 +8,7 @@ def a() -> bool:
     return True
     """
 
-    out = vyper.compile_codes({'': code}, ['opcodes_runtime', 'opcodes'])[0]
+    out = vyper.compile_code(code, ['opcodes_runtime', 'opcodes'])
 
     assert len(out['opcodes']) > len(out['opcodes_runtime'])
     assert out['opcodes_runtime'] in out['opcodes']
diff --git a/tests/parser/functions/test_abi.py b/tests/parser/functions/test_abi.py
index b97a478abd1..22a59af2cfd 100644
--- a/tests/parser/functions/test_abi.py
+++ b/tests/parser/functions/test_abi.py
@@ -1,5 +1,5 @@
 from vyper.compiler import (
-    compile_codes,
+    compile_code,
     mk_full_signature,
 )
 
@@ -56,11 +56,10 @@ def foo(x: uint256) -> bytes[100]:
     return b"hello"
     """
 
-    out = compile_codes(
-        codes={'t.vy': code},
+    out = compile_code(
+        code,
         output_formats=['method_identifiers'],
-        output_type='list'
-    )[0]
+    )
 
     assert out['method_identifiers'] == {
         'foo(uint256)': '0x2fbebd38',
diff --git a/tests/parser/functions/test_interfaces.py b/tests/parser/functions/test_interfaces.py
index 80177bb5655..75010a777d4 100644
--- a/tests/parser/functions/test_interfaces.py
+++ b/tests/parser/functions/test_interfaces.py
@@ -60,7 +60,7 @@ def allowance(_owner: address, _spender: address) -> (uint256, uint256): constan
     def test(_owner: address): modifying
     """
 
-    out = compile_codes({'one.vy': code}, ['external_interface'])[0]
+    out = compile_codes({'one.vy': code}, ['external_interface'])['one.vy']
     out = out['external_interface']
 
     assert interface.strip() == out.strip()
@@ -79,7 +79,7 @@ def test() -> bool:
     """
 
     assert_compile_failed(
-        lambda: compile_codes({'one.vy': code}),
+        lambda: compile_code(code),
         StructureException
     )
 
@@ -121,7 +121,7 @@ def bar() -> uint256:
     return 2
     """
 
-    assert compile_codes({'one.vy': code}, interface_codes=interface_codes)[0]
+    assert compile_code(code, interface_codes=interface_codes)
 
     not_implemented_code = """
 import a as FooBarInterface
@@ -135,7 +135,7 @@ def foo() -> uint256:
     """
 
     assert_compile_failed(
-        lambda: compile_codes({'one.vy': not_implemented_code}, interface_codes=interface_codes)[0],
+        lambda: compile_code(not_implemented_code, interface_codes=interface_codes),
         StructureException
     )
 
diff --git a/vyper/compiler.py b/vyper/compiler.py
index 5adb7bd07f2..0ce1043dd24 100644
--- a/vyper/compiler.py
+++ b/vyper/compiler.py
@@ -215,7 +215,6 @@ def _mk_ast_dict(code, contract_name, interface_codes):
 
 def compile_codes(codes,
                   output_formats=None,
-                  output_type='list',
                   exc_handler=None,
                   interface_codes=None):
     if output_formats is None:
@@ -240,14 +239,17 @@ def compile_codes(codes,
                 else:
                     raise exc
 
-    if output_type == 'list':
-        return list(out.values())
-    elif output_type == 'dict':
-        return out
-    else:
-        raise ValueError(f'Unsupported output type {repr(output_type)}')
+    return out
+
+
+UNKNOWN_CONTRACT_NAME = '<unknown>'
 
 
 def compile_code(code, output_formats=None, interface_codes=None):
-    codes = {'': code}
-    return compile_codes(codes, output_formats, 'list', interface_codes=interface_codes)[0]
+    codes = {UNKNOWN_CONTRACT_NAME: code}
+
+    return compile_codes(
+        codes,
+        output_formats,
+        interface_codes=interface_codes,
+    )[UNKNOWN_CONTRACT_NAME]