diff --git a/src/kyupy/verilog.py b/src/kyupy/verilog.py
index 9336459..2d28034 100644
--- a/src/kyupy/verilog.py
+++ b/src/kyupy/verilog.py
@@ -37,7 +37,6 @@ class SignalDeclaration:
 class VerilogTransformer(Transformer):
     def __init__(self, branchforks=False, tlib=TechLib()):
         super().__init__()
-        self._signal_declarations = {}
         self.branchforks = branchforks
         self.tlib = tlib
 
@@ -46,14 +45,20 @@ class VerilogTransformer(Transformer):
         s = args[0].value
         return s[1:-1] if s[0] == '\\' else s
 
+    @staticmethod
+    def namedpin(args):
+        return tuple(args) if len(args) > 1 else (args[0], None)
+
     @staticmethod
     def instantiation(args):
         pinmap = {}
         for idx, pin in enumerate(args[2:]):
-            if len(pin.children) > 1:
-                pinmap[pin.children[0]] = pin.children[1]
-            else:
-                pinmap[idx] = pin.children[0]
+            p = pin.children[0]
+            if isinstance(p, tuple):  # named pin
+                if p[1] is not None:
+                    pinmap[p[0]] = p[1]
+            else:  # unnamed pin
+                pinmap[idx] = p
         return Instantiation(args[0], args[1], pinmap)
 
     def range(self, args):
@@ -104,14 +109,15 @@ class VerilogTransformer(Transformer):
         positions = {}
         pos = 0
         const_count = 0
-        self._signal_declarations = {}
+        sig_decls = {}
         for decls in args[2:]:  # pass 0: collect signal declarations
             if isinstance(decls, list):
                 if len(decls) > 0 and isinstance(decls[0], SignalDeclaration):
                     for decl in decls:
-                        self._signal_declarations[decl.basename] = decl
+                        if decl.basename not in sig_decls or sig_decls[decl.basename].kind == 'wire':
+                            sig_decls[decl.basename] = decl
         for intf_sig in args[1].children:
-            for name in self._signal_declarations[intf_sig].names:
+            for name in sig_decls[intf_sig].names:
                 positions[name] = pos
                 pos += 1
         assignments = []
@@ -123,7 +129,7 @@ class VerilogTransformer(Transformer):
                         Line(c, (n, self.tlib.pin_index(stmt.type, p)), Node(c, s))
             elif hasattr(stmt, 'data') and stmt.data == 'assign':
                 assignments.append((stmt.children[0], stmt.children[1]))
-        for sd in self._signal_declarations.values():
+        for sd in sig_decls.values():
             if sd.kind == 'output' or sd.kind == 'input':
                 for name in sd.names:
                     n = Node(c, name, kind=sd.kind)
@@ -135,15 +141,15 @@ class VerilogTransformer(Transformer):
             target_sigs = []
             if not isinstance(target, list): target = [target]
             for s in target:
-                if s in self._signal_declarations:
-                    target_sigs += self._signal_declarations[s].names
+                if s in sig_decls:
+                    target_sigs += sig_decls[s].names
                 else:
                     target_sigs.append(s)
             source_sigs = []
             if not isinstance(source, list): source = [source]
             for s in source:
-                if s in self._signal_declarations:
-                    source_sigs += self._signal_declarations[s].names
+                if s in sig_decls:
+                    source_sigs += sig_decls[s].names
                 else:
                     source_sigs.append(s)
             for t, s in zip(target_sigs, source_sigs):
@@ -177,7 +183,7 @@ class VerilogTransformer(Transformer):
                         Line(c, fork, branchfork)
                         fork = branchfork
                     Line(c, fork, (n, self.tlib.pin_index(stmt.type, p)))
-        for sd in self._signal_declarations.values():
+        for sd in sig_decls.values():
             if sd.kind == 'output':
                 for name in sd.names:
                     if name not in c.forks:
@@ -202,7 +208,8 @@ GRAMMAR = r"""
     wire: "wire" range? _namelist ";"
     assign: "assign" sigsel "=" sigsel ";"
     instantiation: name name "(" [ pin ( "," pin )* ] ")" ";"
-    pin: ("." name "(" sigsel? ")" ) | sigsel
+    pin: namedpin | sigsel
+    namedpin: "." name "(" sigsel? ")"
     range: "[" /[0-9]+/ (":" /[0-9]+/)? "]"
     sigsel: name range? | concat
     concat: "{" sigsel ( "," sigsel )*  "}"