diff --git a/loki/transformations/raw_stack_allocator.py b/loki/transformations/raw_stack_allocator.py
index 8b7983340..1d7b9768a 100644
--- a/loki/transformations/raw_stack_allocator.py
+++ b/loki/transformations/raw_stack_allocator.py
@@ -67,6 +67,9 @@ class TemporariesRawStackTransformation(Transformation):
     directive : str, optional
         Can be ``'openmp'`` or ``'openacc'``. If given, insert data sharing clauses for
         the stack derived type, and insert data transfer statements (for OpenACC only).
+    driver_horizontal : str, optional
+        Override string if a separate variable name should be used for the horizontal
+        when allocating the stack in the driver.
     key : str, optional
         Overwrite the key that is used to store analysis results in ``trafo_data``.
     """
@@ -82,16 +85,18 @@ class TemporariesRawStackTransformation(Transformation):
         BasicType.INTEGER: {'kernel': 'K', 'driver': 'I'}
     }
 
-    def __init__(self, block_dim, horizontal,
-                 stack_name='STACK',
-                 local_int_var_name_pattern='JD_{name}',
-                 directive=None, key=None, **kwargs):
+    def __init__(
+            self, block_dim, horizontal, stack_name='STACK',
+            local_int_var_name_pattern='JD_{name}', directive=None,
+            key=None, driver_horizontal=None, **kwargs
+    ):
         super().__init__(**kwargs)
         self.block_dim = block_dim
         self.horizontal = horizontal
         self.stack_name = stack_name
         self.local_int_var_name_pattern = local_int_var_name_pattern
         self.directive = directive
+        self.driver_horizontal = driver_horizontal
 
         if key:
             self._key = key
@@ -229,8 +234,16 @@ def create_stacks_driver(self, routine, stack_dict, successors):
 
                 #Create the stack variable and its type with the correct shape
                 stack_var = self._get_stack_var(routine, dtype, kind)
-                stack_type = stack_var.type.clone(shape=(self._get_horizontal_variable(routine),
-                                                         stack_dict[dtype][kind], kgpblock))
+                horizontal_size = self._get_horizontal_variable(routine)
+                if self.driver_horizontal:
+                    # If override is specified, use a separate horizontal in the driver
+                    horizontal_size = Variable(
+                        name=self.driver_horizontal, scope=routine, type=self.int_type
+                    )
+
+                stack_type = stack_var.type.clone(
+                    shape=(horizontal_size, stack_dict[dtype][kind], kgpblock)
+                )
                 stack_var = stack_var.clone(type=stack_type)
 
                 #Add the variables to the stack_arg_dict with dimensions (:,:,j_block)
diff --git a/scripts/loki_transform.py b/scripts/loki_transform.py
index de8eb3528..088c62de9 100644
--- a/scripts/loki_transform.py
+++ b/scripts/loki_transform.py
@@ -324,7 +324,8 @@ def transform_subroutine(self, routine, **kwargs):
         ))
 
         transformation = TemporariesRawStackTransformation(
-            block_dim=block_dim, horizontal=horizontal, directive=directive
+            block_dim=block_dim, horizontal=horizontal,
+            directive=directive, driver_horizontal='NPROMA'
         )
         scheduler.process(transformation=transformation)