diff --git a/lib/sql.py b/lib/sql.py
index 8be6542e..de93fdc6 100644
--- a/lib/sql.py
+++ b/lib/sql.py
@@ -30,7 +30,7 @@ import collections
 from psycopg2 import extensions as ext
 
 
-class Composible(object):
+class Composable(object):
     """Base class for objects that can be used to compose an SQL string."""
     def as_string(self, conn_or_curs):
         raise NotImplementedError
@@ -38,19 +38,19 @@ class Composible(object):
     def __add__(self, other):
         if isinstance(other, Composed):
             return Composed([self]) + other
-        if isinstance(other, Composible):
+        if isinstance(other, Composable):
             return Composed([self]) + Composed([other])
         else:
             return NotImplemented
 
 
-class Composed(Composible):
+class Composed(Composable):
     def __init__(self, seq):
         self._seq = []
         for i in seq:
-            if not isinstance(i, Composible):
+            if not isinstance(i, Composable):
                 raise TypeError(
-                    "Composed elements must be Composible, got %r instead" % i)
+                    "Composed elements must be Composable, got %r instead" % i)
             self._seq.append(i)
 
     def __repr__(self):
@@ -65,7 +65,7 @@ class Composed(Composible):
     def __add__(self, other):
         if isinstance(other, Composed):
             return Composed(self._seq + other._seq)
-        if isinstance(other, Composible):
+        if isinstance(other, Composable):
             return Composed(self._seq + [other])
         else:
             return NotImplemented
@@ -92,7 +92,7 @@ class Composed(Composible):
         return Composed(rv)
 
 
-class SQL(Composible):
+class SQL(Composable):
     def __init__(self, wrapped):
         if not isinstance(wrapped, basestring):
             raise TypeError("SQL values must be strings")
@@ -122,7 +122,7 @@ class SQL(Composible):
         return Composed(rv)
 
 
-class Identifier(Composible):
+class Identifier(Composable):
     def __init__(self, wrapped):
         if not isinstance(wrapped, basestring):
             raise TypeError("SQL identifiers must be strings")
@@ -140,7 +140,7 @@ class Identifier(Composible):
         return ext.quote_ident(self._wrapped, conn_or_curs)
 
 
-class Literal(Composible):
+class Literal(Composable):
     def __init__(self, wrapped):
         self._wrapped = wrapped
 
@@ -170,7 +170,7 @@ class Literal(Composible):
         return Composed([self] * n)
 
 
-class Placeholder(Composible):
+class Placeholder(Composable):
     def __init__(self, name=None):
         if isinstance(name, basestring):
             if ')' in name:
diff --git a/psycopg/cursor_type.c b/psycopg/cursor_type.c
index adb3d0f3..5031033c 100644
--- a/psycopg/cursor_type.c
+++ b/psycopg/cursor_type.c
@@ -267,7 +267,7 @@ _mogrify(PyObject *var, PyObject *fmt, cursorObject *curs, PyObject **new)
     return 0;
 }
 
-/* Return 1 if `obj` is a `psycopg2.sql.Composible` instance, else 0
+/* Return 1 if `obj` is a `psycopg2.sql.Composable` instance, else 0
  * Set an exception and return -1 in case of error.
  */
 RAISES_NEG static int
@@ -278,7 +278,7 @@ _curs_is_composible(PyObject *obj)
     PyObject *comp = NULL;
 
     if (!(m = PyImport_ImportModule("psycopg2.sql"))) { goto exit; }
-    if (!(comp = PyObject_GetAttrString(m, "Composible"))) { goto exit; }
+    if (!(comp = PyObject_GetAttrString(m, "Composable"))) { goto exit; }
     rv = PyObject_IsInstance(obj, comp);
 
 exit:
diff --git a/tests/test_sql.py b/tests/test_sql.py
index f7c0801b..3a90ef3a 100755
--- a/tests/test_sql.py
+++ b/tests/test_sql.py
@@ -117,7 +117,7 @@ class ComposeTests(ConnectingTestCase):
 
 class IdentifierTests(ConnectingTestCase):
     def test_class(self):
-        self.assert_(issubclass(sql.Identifier, sql.Composible))
+        self.assert_(issubclass(sql.Identifier, sql.Composable))
 
     def test_init(self):
         self.assert_(isinstance(sql.Identifier('foo'), sql.Identifier))
@@ -140,7 +140,7 @@ class IdentifierTests(ConnectingTestCase):
 
 class LiteralTests(ConnectingTestCase):
     def test_class(self):
-        self.assert_(issubclass(sql.Literal, sql.Composible))
+        self.assert_(issubclass(sql.Literal, sql.Composable))
 
     def test_init(self):
         self.assert_(isinstance(sql.Literal('foo'), sql.Literal))
@@ -164,7 +164,7 @@ class LiteralTests(ConnectingTestCase):
 
 class SQLTests(ConnectingTestCase):
     def test_class(self):
-        self.assert_(issubclass(sql.SQL, sql.Composible))
+        self.assert_(issubclass(sql.SQL, sql.Composable))
 
     def test_init(self):
         self.assert_(isinstance(sql.SQL('foo'), sql.SQL))
@@ -202,7 +202,7 @@ class SQLTests(ConnectingTestCase):
 
 class ComposedTest(ConnectingTestCase):
     def test_class(self):
-        self.assert_(issubclass(sql.Composed, sql.Composible))
+        self.assert_(issubclass(sql.Composed, sql.Composable))
 
     def test_repr(self):
         obj = sql.Composed([sql.Literal("foo"), sql.Identifier("b'ar")])
@@ -236,7 +236,7 @@ class ComposedTest(ConnectingTestCase):
 
 class PlaceholderTest(ConnectingTestCase):
     def test_class(self):
-        self.assert_(issubclass(sql.Placeholder, sql.Composible))
+        self.assert_(issubclass(sql.Placeholder, sql.Composable))
 
     def test_alias(self):
         self.assert_(sql.Placeholder is sql.PH)