diff --git a/README.rst b/README.rst
index 4bc54392..98bd32c9 100644
--- a/README.rst
+++ b/README.rst
@@ -44,7 +44,7 @@ The following dependencies are needed.
 The following are optional dependencies that allow other solvers to be used.
 
 -  `cplex <https://www-01.ibm.com/software/commerce/optimization/cplex-optimizer/>`__ (LP, MILP, QP, MIQP)
--  `gurobipy <http://www.gurobi.com>`__ (LP, MILP (QP and MIQP support will be added in the future))
+-  `gurobipy <http://www.gurobi.com>`__ (LP, MILP, QP, MIQP)
 -  `scipy <http://www.scipy.org>`__ (LP)
 
 
@@ -134,9 +134,6 @@ Future outlook
    `CPLEX <http://www-01.ibm.com/software/commerce/optimization/cplex-optimizer/>`__
    etc.)
 
-The optlang `trello board <https://trello.com/b/aiwfbVKO/optlang>`__
-also provides a good overview of the project's roadmap.
-
 .. |PyPI| image:: https://img.shields.io/pypi/v/optlang.svg?maxAge=2592000
    :target: https://pypi.python.org/pypi/optlang
 .. |License| image:: http://img.shields.io/badge/license-APACHE2-blue.svg
diff --git a/optlang/cplex_interface.py b/optlang/cplex_interface.py
index 20868731..2ce5cfed 100644
--- a/optlang/cplex_interface.py
+++ b/optlang/cplex_interface.py
@@ -470,7 +470,7 @@ class ResultsStreamHandler(StreamHandler):
             def flush(self):
                 self.logger.debug(self.getvalue())
 
-        logger = logging.getLogger()
+        logger = logging.getLogger(__name__ + ".Model")  # TODO: Make the logger name specific to each solver instance
         logger.setLevel(logging.CRITICAL)
         error_stream_handler = ErrorStreamHandler(logger)
         warning_stream_handler = WarningStreamHandler(logger)
diff --git a/optlang/expression_parsing.py b/optlang/expression_parsing.py
index b83c68f6..1dc0b4cc 100644
--- a/optlang/expression_parsing.py
+++ b/optlang/expression_parsing.py
@@ -13,7 +13,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from optlang.symbolics import One
+from optlang.symbolics import Integer
+
+one = Integer(1)
 
 
 def parse_optimization_expression(obj, linear=True, quadratic=False, expression=None, **kwargs):
@@ -84,7 +86,7 @@ def _parse_linear_expression(expression, expanded=False, **kwargs):
 
     for var in coefficients:
         if not (var.is_Symbol):
-            if var == One:
+            if var == one:
                 constant = var
                 offset = float(coefficients[var])
             elif expanded:
diff --git a/optlang/gurobi_interface.py b/optlang/gurobi_interface.py
index c8f4a345..0cba066f 100644
--- a/optlang/gurobi_interface.py
+++ b/optlang/gurobi_interface.py
@@ -402,10 +402,10 @@ class Configuration(interface.MathematicalProgrammingConfiguration):
     def __init__(self, lp_method='primal', qp_method='primal', presolve=False,
                  verbosity=0, timeout=None, *args, **kwargs):
         super(Configuration, self).__init__(*args, **kwargs)
+        self.verbosity = verbosity
         self.lp_method = lp_method
         self.qp_method = qp_method
         self.presolve = presolve
-        self.verbosity = verbosity
         self.timeout = timeout
 
     @property
diff --git a/optlang/interface.py b/optlang/interface.py
index c86144ce..3576c7c0 100644
--- a/optlang/interface.py
+++ b/optlang/interface.py
@@ -33,6 +33,7 @@
 
 import six
 
+import optlang
 from optlang.exceptions import IndicatorConstraintsNotSupported
 
 from optlang.util import parse_expr, expr_to_json, is_numeric, SolverTolerances
@@ -463,7 +464,8 @@ def _canonicalize(self, expression):
         elif isinstance(expression, int):
             return symbolics.Integer(expression)
         else:
-            # expression = expression.expand() This would be a good way to canonicalize, but is quite slow
+            if optlang._USING_SYMENGINE:
+                expression = expression.expand()  # This is a good way to canonicalize, but is quite slow for sympy
             return expression
 
     @property
@@ -1630,6 +1632,4 @@ def __setstate__(self, state):
 
     # model.remove(x1)
 
-    import optlang
-
     model.interface = optlang.glpk_interface
diff --git a/optlang/scipy_interface.py b/optlang/scipy_interface.py
index 0d82b878..dea8c556 100644
--- a/optlang/scipy_interface.py
+++ b/optlang/scipy_interface.py
@@ -418,6 +418,7 @@ def coefficient_dict(self, names=True):
         if self.expression.is_Add:
             coefficient_dict = {variable: coef for variable, coef in
                                 self.expression.as_coefficients_dict().items() if variable.is_Symbol}
+            coefficient_dict = {var: float(coef) for var, coef in coefficient_dict.items()}
         elif self.expression.is_Atom and self.expression.is_Symbol:
             coefficient_dict = {self.expression: 1}
         elif self.expression.is_Mul and len(self.expression.args) <= 2:
@@ -496,7 +497,7 @@ def coefficient_dict(self):
             coefficient_dict = {}
         else:
             raise ValueError("Invalid expression: " + str(self.expression))
-        coefficient_dict = {var.name: coef for var, coef in coefficient_dict.items()}
+        coefficient_dict = {var.name: float(coef) for var, coef in coefficient_dict.items()}
         return coefficient_dict
 
     def set_linear_coefficients(self, coefficients):
@@ -509,7 +510,7 @@ def set_linear_coefficients(self, coefficients):
     def get_linear_coefficients(self, variables):
         if self.problem is not None:
             self.problem.update()
-            return {v: self.problem.problem.objective.get(v.name, 0) for v in variables}
+            return {v: float(self.problem.problem.objective.get(v.name, 0)) for v in variables}
         else:
             raise Exception("Can't get coefficients from solver if objective is not in a model")
 
diff --git a/optlang/symbolics.py b/optlang/symbolics.py
index f9bdeb5e..228eda86 100644
--- a/optlang/symbolics.py
+++ b/optlang/symbolics.py
@@ -58,9 +58,9 @@
     Real = symengine.RealDouble
     Basic = symengine.Basic
     Number = symengine.Number
-    Zero = Integer(0)
-    One = Integer(1)
-    NegativeOne = Integer(-1)
+    Zero = Real(0)
+    One = Real(1)
+    NegativeOne = Real(-1)
     sympify = symengine.sympy_compat.sympify
 
     Add = symengine.Add
@@ -113,9 +113,9 @@ def mul(*args):
     Real = sympy.RealNumber
     Basic = sympy.Basic
     Number = sympy.Number
-    Zero = Integer(0)
-    One = Integer(1)
-    NegativeOne = Integer(-1)
+    Zero = Real(0)
+    One = Real(1)
+    NegativeOne = Real(-1)
     sympify = sympy.sympify
 
     Add = sympy.Add
diff --git a/optlang/tests/abstract_test_cases.py b/optlang/tests/abstract_test_cases.py
index 9dc49a75..133cf53d 100644
--- a/optlang/tests/abstract_test_cases.py
+++ b/optlang/tests/abstract_test_cases.py
@@ -20,6 +20,7 @@
 
 import six
 from optlang import interface
+from optlang import symbolics
 import optlang
 import pickle
 import json
@@ -350,6 +351,18 @@ def test_new_invalid_name_raises(self):
         with self.assertRaises(Exception):
             const.name = "This\ttab"
 
+    def test_construct_with_sloppy(self):
+        x, y, z, w = self.model.variables[:4]
+        const = self.interface.Constraint(
+            symbolics.add([symbolics.mul(symbolics.One, var) for var in [x, y, z]]),
+            lb=0,
+            sloppy=True
+        )
+        self.model.add(const)
+        self.model.update()
+
+        self.assertTrue(const.get_linear_coefficients([x, y, z, w]) == {x: 1, y: 1, z: 1, w: 0})
+
 
 @six.add_metaclass(abc.ABCMeta)
 class AbstractObjectiveTestCase(unittest.TestCase):
@@ -390,6 +403,17 @@ def test_new_invalid_name_raises(self):
         with self.assertRaises(Exception):
             obj.name = "This\ttab"
 
+    def test_construct_with_sloppy(self):
+        x, y, z, w = self.model.variables[:4]
+        obj = self.interface.Objective(
+            symbolics.add([symbolics.mul((symbolics.One, var)) for var in [x, y, z]]),
+            direction="min",
+            sloppy=True
+        )
+        self.model.objective = obj
+
+        self.assertTrue(obj.get_linear_coefficients([x, y, z, w]) == {x: 1, y: 1, z: 1, w: 0})
+
 
 @six.add_metaclass(abc.ABCMeta)
 class AbstractModelTestCase(unittest.TestCase):
diff --git a/optlang/tests/test_expression_parsing.py b/optlang/tests/test_expression_parsing.py
index 2b307b82..f03f6eb3 100644
--- a/optlang/tests/test_expression_parsing.py
+++ b/optlang/tests/test_expression_parsing.py
@@ -68,10 +68,18 @@ def test_parse_non_expanded_quadratic_expression(self):
         target = {frozenset([x]): 1, frozenset([y]): 1, frozenset([x, y]): 2, frozenset([z]): -1}
         linear_target = {z: 4}
 
-        offset_const, linear_terms_const, quad_terms_const = parse_optimization_expression(Constraint(expr, lb=0), quadratic=True)
-        offset_obj, linear_terms_obj, quad_terms_obj = parse_optimization_expression(Objective(expr), linear=False)
-
-        self.assertEqual(offset_const, -4)
+        constraint = Constraint(expr, lb=0)
+        offset_const, linear_terms_const, quad_terms_const = parse_optimization_expression(
+            constraint,
+            quadratic=True
+        )
+        offset_obj, linear_terms_obj, quad_terms_obj = parse_optimization_expression(
+            Objective(expr),
+            expression=expr,
+            linear=False
+        )
+
+        self.assertEqual(offset_const - constraint.lb, -4 + offset)
         self.assertEqual(offset_obj, -4 + offset)
         _compare_term_dicts(self, linear_terms_const, linear_target)
         _compare_term_dicts(self, linear_terms_obj, linear_target)
diff --git a/optlang/tests/test_symbolics.py b/optlang/tests/test_symbolics.py
index 22655344..92fd06d7 100644
--- a/optlang/tests/test_symbolics.py
+++ b/optlang/tests/test_symbolics.py
@@ -5,7 +5,7 @@
 class SymbolicsTestCase(unittest.TestCase):
 
     def test_add_identity(self):
-        self.assertEqual(optlang.symbolics.add(), 0)
+        self.assertEqual(optlang.symbolics.add(), 0.0)
 
     def test_mul_identity(self):
-        self.assertEqual(optlang.symbolics.mul(), 1)
+        self.assertEqual(optlang.symbolics.mul(), 1.0)