diff --git a/kernel_tuner/searchspace.py b/kernel_tuner/searchspace.py
index d3d00052..42d0be4d 100644
--- a/kernel_tuner/searchspace.py
+++ b/kernel_tuner/searchspace.py
@@ -7,6 +7,7 @@
 from warnings import warn
 from copy import deepcopy
 from collections import defaultdict, deque
+from inspect import signature
 
 import numpy as np
 from scipy.stats.qmc import LatinHypercube
@@ -495,6 +496,13 @@ def __build_searchspace(self, block_size_names: list, max_threads: int, solver:
     def __add_restrictions(self, parameter_space: Problem) -> Problem:
         """Add the user-specified restrictions as constraints on the parameter space."""
         restrictions = deepcopy(self.restrictions)
+        # differentiate between old style monolithic with single 'p' argument and newer *args style
+        if (len(restrictions) == 1
+            and not isinstance(restrictions[0], (Constraint, FunctionConstraint, str))
+            and callable(restrictions[0])
+            and len(signature(restrictions[0]).parameters) == 1
+            and len(self.param_names) > 1):
+            restrictions = restrictions[0]
         if isinstance(restrictions, list):
             for restriction in restrictions:
                 required_params = self.param_names
@@ -504,10 +512,6 @@ def __add_restrictions(self, parameter_space: Problem) -> Problem:
                     required_params = restriction[1]
                     restriction = restriction[0]
                 if callable(restriction) and not isinstance(restriction, Constraint):
-                    # def restrictions_wrapper(*args):
-                    #     return check_instance_restrictions(restriction, dict(zip(self.param_names, args)), False)
-                    # print(restriction, isinstance(restriction, Constraint))
-                    # restriction = FunctionConstraint(restrictions_wrapper)
                     restriction = FunctionConstraint(restriction, required_params)
 
                 # add as a Constraint
@@ -529,6 +533,7 @@ def __add_restrictions(self, parameter_space: Problem) -> Problem:
         elif callable(restrictions):
 
             def restrictions_wrapper(*args):
+                """Wrap old-style monolithic restrictions to work with multiple arguments."""
                 return check_instance_restrictions(restrictions, dict(zip(self.param_names, args)), False)
 
             parameter_space.addConstraint(FunctionConstraint(restrictions_wrapper), self.param_names)
diff --git a/test/test_searchspace.py b/test/test_searchspace.py
index f742a4b7..32f58bec 100644
--- a/test/test_searchspace.py
+++ b/test/test_searchspace.py
@@ -623,3 +623,37 @@ def test_full_searchspace(compare_against_bruteforce=False):
         compare_two_searchspace_objects(searchspace, searchspace_bruteforce)
     else:
         assert searchspace.size == len(searchspace.list) == 349853
+
+def test_restriction_backwards_compatibility():
+    """Test whether the backwards compatibility code for restrictions (list of strings) works as expected."""
+    # create a searchspace with mixed parameter types
+    max_threads = 1024
+    tune_params = dict()
+    tune_params["N_PER_BLOCK"] = [32, 64, 128, 256, 512, 1024]
+    tune_params["M_PER_BLOCK"] = [32, 64, 128, 256, 512, 1024]
+    tune_params["block_size_y"] = [1, 2, 4, 8, 16, 32]
+    tune_params["block_size_z"] = [1, 2, 4, 8, 16, 32]
+
+    # old style monolithic restriction function
+    def restrict(p):
+        n_global_per_warp = int(p["N_PER_BLOCK"] // p["block_size_y"])
+        m_global_per_warp = int(p["M_PER_BLOCK"] // p["block_size_z"])
+        if n_global_per_warp == 0 or m_global_per_warp == 0:
+            return False
+
+    searchspace_callable = Searchspace(tune_params, restrict, max_threads)
+
+    def restrict_args(N_PER_BLOCK, M_PER_BLOCK, block_size_y, block_size_z):
+        n_global_per_warp = int(N_PER_BLOCK // block_size_y)
+        m_global_per_warp = int(M_PER_BLOCK // block_size_z)
+        if n_global_per_warp == 0 or m_global_per_warp == 0:
+            return False
+
+    # args-style restriction
+    searchspace_str = Searchspace(tune_params, restrict_args, max_threads)
+
+    # check the size
+    assert searchspace_str.size == searchspace_callable.size
+
+    # check that both searchspaces are identical in outcome
+    compare_two_searchspace_objects(searchspace_str, searchspace_callable)