diff --git a/coffee/base.py b/coffee/base.py
index c8f4d030..3bf2f55b 100644
--- a/coffee/base.py
+++ b/coffee/base.py
@@ -36,7 +36,7 @@
 from __future__ import absolute_import, print_function, division
 
 from copy import deepcopy as dcopy
-from math import isnan
+from cmath import isnan
 import numbers
 import numpy as np
 
@@ -171,6 +171,7 @@ def __deepcopy__(self, memo):
 
     def gencode(self, not_scope=True, parent=None):
         children = [n.gencode(not_scope, self) for n in self.children]
+        children = ["("+child+")" for child in children]
         subtree = (" "+type(self).op+" ").join(children)
         if parent:
             return wrap(subtree)
@@ -259,9 +260,12 @@ def values(self, val):
         self._values = val
 
     def _formatter(self, v):
-        """Format a float into a string, showing up to ``precision`` decimal digits.
-        This function is partly extracted from the open_source "FFC: the FEniCS Form
-        Compiler", freely accessible at https://bitbucket.org/fenics-project/ffc."""
+        """Format a real or complex value into a string, showing up to
+        ``precision`` decimal digits.  This function is partly
+        extracted from the open_source "FFC: the FEniCS Form
+        Compiler", freely accessible at
+        https://bitbucket.org/fenics-project/ffc.
+        """
         f = "%%.%dg" % self.precision
         f_int = "%%.%df" % 1
         eps = 10.0**(-self.precision)
@@ -269,10 +273,12 @@ def _formatter(self, v):
             return v.gencode(not_scope=True)
         elif isnan(v):
             return "NAN"
-        elif abs(v - round(v, 1)) < eps:
-            return f_int % v
+        elif abs(v.real - round(v.real, 1)) < eps and abs(v.imag - round(v.imag, 1)) < eps:
+            formatter = f_int
         else:
-            return f % v
+            formatter = f
+        re, im, zero = map(lambda arg: formatter % arg, (v.real, v.imag, 0))
+        return re if im == zero else re + ' + ' + im + ' * I'
 
     def _tabulate_values(self, arr):
         if len(arr.shape) == 1:
@@ -468,7 +474,7 @@ def is_const(self):
     @property
     def is_number(self):
         try:
-            float(self.symbol)
+            complex(self.symbol)
             return True
         except ValueError:
             return False
@@ -1153,6 +1159,34 @@ def gencode(self, not_scope=True):
 """ % (str(dim), str(lda), str(sym), str(sym))
 
 
+class ComplexInvert(Statement, LinAlg):
+    """In-place inversion of a square array."""
+    # this should probably be changed later to not require a real and complex version
+    def __init__(self, sym, dim, pragma=None):
+        super(ComplexInvert, self).__init__([sym, dim, dim], pragma)
+
+    def reconstruct(self, sym, dim, **kwargs):
+        return type(self)(sym, dim, **kwargs)
+
+    def operands(self):
+        return [self.children[0], self.children[1]], {'pragma': self.pragma}
+
+    def gencode(self, not_scope=True):
+        sym, dim, lda = self.children
+        return """{
+  int n = %s;
+  int lda = %s;
+  int ipiv[n];
+  int lwork = n*n;
+  double complex work[lwork];
+  int info;
+
+  zgetrf_(&n,&n,%s,&lda,ipiv,&info);
+  zgetri_(&n,%s,&lda,ipiv,work,&lwork,&info);
+}
+""" % (str(dim), str(lda), str(sym), str(sym))
+
+
 class Determinant(Expr, LinAlg):
     """Generic determinant"""
     def __init__(self, sym, pragma=None):
diff --git a/coffee/visitor.py b/coffee/visitor.py
index bf0ea69d..12ea3bb6 100644
--- a/coffee/visitor.py
+++ b/coffee/visitor.py
@@ -44,8 +44,8 @@ def __init__(self):
             # Check the argument specification
             # Valid options are:
             #    visit_Foo(self, o, [*args, **kwargs])
-            signature = inspect.signature(meth)
-            if len(signature.parameters) < 2:
+            argspec = inspect.getfullargspec(meth)
+            if len(argspec.args) < 2:
                 raise RuntimeError("Visit method signature must be visit_Foo(self, o, [*args, **kwargs])")
             handlers[name[len(prefix):]] = meth
         self._handlers = handlers
diff --git a/tests/test_precedence.py b/tests/test_precedence.py
index e30d82a7..7566b37a 100644
--- a/tests/test_precedence.py
+++ b/tests/test_precedence.py
@@ -6,10 +6,10 @@
 def test_prod_div():
     tree = ast.Prod("a", ast.Div("1", "b"))
 
-    assert tree.gencode() == "a * (1 / b)"
+    assert tree.gencode() == "(a) * (((1) / (b)))"
 
 
 def test_unary_op():
     tree = ast.Not(ast.Or("a", ast.And("b", "c")))
 
-    assert tree.gencode() == "!(a || (b && c))"
+    assert tree.gencode() == "!((a) || (((b) && (c))))"