diff --git a/RELEASE.md b/RELEASE.md
index 66c65a56..539aed38 100644
--- a/RELEASE.md
+++ b/RELEASE.md
@@ -2,6 +2,7 @@
 - Migrated to Pint >= 0.24 (the `ScaleConverter` and `UnitDefinition` classes moved to `pint.facets.plain` and changed argument signatures). This reverses the `Pint < 0.20` pin introduced in 0.3.5 and restores compatibility with numpy 2.x, which older Pint versions could not import.
 - Added support for Python 3.14.
 - Dropped support for Python 3.9 as Pint >= 0.24 requires Python >= 3.10.
+- Added support for sympy 1.13 and 1.14 (minimum supported sympy version is now 1.10).
 
 # Release 0.3.7
 - Added support for Python 3.12 and 3.13.
diff --git a/cellmlmanip/_singularity_fixes.py b/cellmlmanip/_singularity_fixes.py
index 696dead1..447df455 100644
--- a/cellmlmanip/_singularity_fixes.py
+++ b/cellmlmanip/_singularity_fixes.py
@@ -293,7 +293,8 @@ def _fix_expr_parts(expr, V, U_offset, exp_function):
                 expr_parts.append(_generate_piecewise(ex, V, sp, Vmin, Vmax) if sp is not None else ex)
             return (None, None, None, Add(*expr_parts), is_piecewise)
 
-    elif isinstance(expr, Pow) and expr.args[1] == -1.0 and len(expr.args) == 2:  # 1/A
+    # 1/A
+    elif isinstance(expr, Pow) and len(expr.args) == 2 and expr.args[1].is_number and float(expr.args[1]) == -1.0:
         # Find singularities in A and adjust result to represent 1 / A
         Vmin, Vmax, sp, ex, has_piecewise = _fix_expr_parts(expr.args[0], V, U_offset, exp_function)
         has_piecewise = has_piecewise or Vmin is not None
diff --git a/cellmlmanip/units.py b/cellmlmanip/units.py
index 2fa25844..3656e1b3 100644
--- a/cellmlmanip/units.py
+++ b/cellmlmanip/units.py
@@ -136,7 +136,6 @@ def __init__(self, store=None):
         self._calculator = UnitCalculator(self)
 
         # Expose the Unit and Quantity classes
-        # TODO Might not be needed in 0.10 anymore
         self.Unit = self._registry.Unit
         self.Quantity = self._registry.Quantity
 
@@ -164,7 +163,6 @@ def add_unit(self, name, expression):
         # Add prefixes inside expression
         expression = _WORD.sub(self._prefix_expression, expression)
 
-        # Dimensionless units can't be created using a string expression.
         # To test if this is a dimensionless unit, parse the string as a Quantity and check if it's dimensionless
         quantity = self._registry.parse_expression(expression)
         if quantity.units == self._registry.dimensionless:
@@ -277,10 +275,6 @@ def get_conversion_factor(self, from_unit, to_unit):
         cf = self.convert(1 * from_unit, to_unit).magnitude
         if isinstance(cf, numbers.Number) and math.isclose(cf, 1.0):
             return 1
-        elif isinstance(cf, sympy.Mul) and 1.0 in cf.args:  # pragma: no cover
-            # We get an ugly artefact whereby pint gives us a 1.0*cf as conversion factor; remove the 1.0
-            # But only on older pint, e.g. 3.9
-            return sympy.Mul(*[a for a in cf.args if a != 1.0])
         return cf
 
     def convert(self, quantity, unit):
diff --git a/pyproject.toml b/pyproject.toml
index 7dc687b6..c7236a62 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -26,10 +26,10 @@ classifiers = [
 ]
 dependencies = [
     "lxml>=4.7",
-    "networkx>=2.1",
-    "Pint>=0.24, <0.26",
-    "rdflib>=4",
-    "sympy>=1.4, <1.13",
+    "networkx>=2.7",
+    "Pint>=0.24, <0.26",  # Occasional breaking changes in minor versions
+    "rdflib>=6.2",
+    "sympy>=1.10, <1.15",  # Occasional breaking changes in minor versions
 ]
 dynamic = ["version"]
 
diff --git a/requirements/base.in b/requirements/base.in
index bfe658df..79bc28a5 100644
--- a/requirements/base.in
+++ b/requirements/base.in
@@ -1,5 +1,5 @@
 lxml>=4.7
 pint>=0.24, <0.26
-rdflib>=4
-networkx>=2.1
-sympy>=1.4, <1.13
+rdflib>=6.2
+networkx>=2.7
+sympy>=1.10, <1.15
diff --git a/requirements/base.txt b/requirements/base.txt
index 3ec581cf..8d301a54 100644
--- a/requirements/base.txt
+++ b/requirements/base.txt
@@ -24,7 +24,7 @@ pyparsing==3.3.2
     # via rdflib
 rdflib==7.6.0
     # via -r base.in
-sympy==1.12.1
+sympy==1.14.0
     # via -r base.in
 typing-extensions==4.16.0
     # via
diff --git a/requirements/dev.txt b/requirements/dev.txt
index 4eb5f097..7f661190 100644
--- a/requirements/dev.txt
+++ b/requirements/dev.txt
@@ -71,7 +71,7 @@ pytest-cov==7.1.0
     # via -r test.in
 rdflib==7.6.0
     # via -r base.in
-sympy==1.12.1
+sympy==1.14.0
     # via -r base.in
 tomli==2.4.1
     # via
diff --git a/requirements/test.txt b/requirements/test.txt
index 63a91dd9..62a76433 100644
--- a/requirements/test.txt
+++ b/requirements/test.txt
@@ -54,7 +54,7 @@ pytest-cov==7.1.0
     # via -r test.in
 rdflib==7.6.0
     # via -r base.in
-sympy==1.12.1
+sympy==1.14.0
     # via -r base.in
 tomli==2.4.1
     # via
diff --git a/tests/test_transpiler.py b/tests/test_transpiler.py
index 0670bb8b..6b5ea776 100644
--- a/tests/test_transpiler.py
+++ b/tests/test_transpiler.py
@@ -34,7 +34,7 @@ def test_symbol(self):
 
     def test_number(self):
         self.assert_equal('<cn>1</cn>',
-                          [sympy.Number(1)])
+                          [sympy.Number(1.0)])
 
     def test_ignore_comment(self):
         self.assert_equal('<!-- ignore this -->', [])