diff --git a/dwave/cloud/solver.py b/dwave/cloud/solver.py
index 8f24b92a..9a54bf06 100644
--- a/dwave/cloud/solver.py
+++ b/dwave/cloud/solver.py
@@ -53,9 +53,6 @@ class Solver(object):
 
     """
 
-    # Special flag to notify the system a solver needs access to special hardware
-    _PARAMETER_ENABLE_HARDWARE = 'use_hardware'
-
     # Classes of problems the remote solver has to support (at least one of these)
     # in order for `Solver` to be able to abstract, or use, that solver
     _HANDLED_PROBLEM_TYPES = {"ising", "qubo"}
@@ -126,11 +123,6 @@ def __init__(self, client, data):
         # Create a set of default parameters for the queries
         self._params = {}
 
-        # As a heuristic to guess if this is a hardware sampler check if
-        # the 'annealing_time_range' property is set.
-        if 'annealing_time_range' in self.properties:
-            self._params[self._PARAMETER_ENABLE_HARDWARE] = True
-
     def __repr__(self):
         return "Solver(id={!r})".format(self.id)
 
@@ -259,7 +251,7 @@ def _sample(self, type_, linear, quadratic, params):
 
         # Check the parameters before submitting
         for key in combined_params:
-            if key not in self.parameters and key != self._PARAMETER_ENABLE_HARDWARE:
+            if key not in self.parameters and not key.startswith('x_'):
                 raise KeyError("{} is not a parameter of this solver.".format(key))
 
         body = json.dumps({
diff --git a/tests/test_solver.py b/tests/test_solver.py
index e745b1ed..a9174d23 100644
--- a/tests/test_solver.py
+++ b/tests/test_solver.py
@@ -14,7 +14,7 @@
 
 from dwave.cloud.utils import evaluate_ising
 from dwave.cloud.qpu import Client
-from dwave.cloud.exceptions import CanceledFutureError
+from dwave.cloud.exceptions import CanceledFutureError, SolverFailureError
 import dwave.cloud.computation
 
 from tests import config
@@ -44,6 +44,14 @@ def test_submit_invalid_parameter(self):
             with self.assertRaises(KeyError):
                 solver.sample_ising({}, {}, not_a_parameter=True)
 
+    def test_submit_experimental_parameter(self):
+        """Ensure that the experimental parameters are populated."""
+        with Client(**config) as client:
+            solver = client.get_solver()
+            assert 'x_test' not in solver.parameters
+            with self.assertRaises(SolverFailureError):
+                self.assertTrue(solver.sample_ising([0], {}, x_test=123).result())
+
     def test_read_connectivity(self):
         """Ensure that the edge set is populated."""
         with Client(**config) as client: