diff --git a/lib/galaxy/tools/parameters/basic.py b/lib/galaxy/tools/parameters/basic.py
index 4436e21d35d..6c7e75e3bef 100644
--- a/lib/galaxy/tools/parameters/basic.py
+++ b/lib/galaxy/tools/parameters/basic.py
@@ -512,12 +512,12 @@ class IntegerToolParameter(TextToolParameter):
     def to_python(self, value, app):
         try:
             return int(value)
-        except (TypeError, ValueError) as err:
+        except (TypeError, ValueError):
             if contains_workflow_parameter(value):
                 return value
             if not value and self.optional:
                 return None
-            raise err
+            raise ParameterValueError("an integer is required", self.name, value)
 
     def get_initial_value(self, trans, other_values):
         if self.value is not None and self.value != "":
@@ -585,12 +585,12 @@ class FloatToolParameter(TextToolParameter):
     def to_python(self, value, app):
         try:
             return float(value)
-        except (TypeError, ValueError) as err:
+        except (TypeError, ValueError):
             if contains_workflow_parameter(value):
                 return value
             if not value and self.optional:
                 return None
-            raise err
+            raise ParameterValueError("a float is required", self.name, value)
 
     def get_initial_value(self, trans, other_values):
         if self.value is None:
diff --git a/test/unit/app/tools/test_parameter_validation.py b/test/unit/app/tools/test_parameter_validation.py
index 712b184498b..58b149462a3 100644
--- a/test/unit/app/tools/test_parameter_validation.py
+++ b/test/unit/app/tools/test_parameter_validation.py
@@ -5,6 +5,7 @@ from galaxy.model import (
     History,
     HistoryDatasetAssociation,
 )
+from galaxy.tools.parameters.basic import ParameterValueError
 from galaxy.util import galaxy_directory
 from .util import BaseParameterTestCase
 
@@ -415,3 +416,15 @@ class TestParameterValidation(BaseParameterTestCase):
         p.validate("select id from job where id = 1;")
         with self.assertRaises(ValueError):
             p.validate("not sql")
+
+    def test_integer_to_python_raises_parameter_value_error(self):
+        p = self._parameter_for(xml='<param name="num" type="integer" value="10" />')
+        assert p.to_python(42, self.app) == 42
+        with self.assertRaises(ParameterValueError):
+            p.to_python(None, self.app)
+
+    def test_float_to_python_raises_parameter_value_error(self):
+        p = self._parameter_for(xml='<param name="num" type="float" value="1.0" />')
+        assert p.to_python(3.14, self.app) == 3.14
+        with self.assertRaises(ParameterValueError):
+            p.to_python(None, self.app)