diff --git a/src/dcegm/pre_processing/state_space.py b/src/dcegm/pre_processing/state_space.py
index e12956fd..12b5a2f9 100644
--- a/src/dcegm/pre_processing/state_space.py
+++ b/src/dcegm/pre_processing/state_space.py
@@ -185,19 +185,18 @@ def create_state_space(options):
         (state_space_wo_exog_full, exog_state_space_full), axis=1
     )
 
-    dtype_state_space = get_smallest_uint_type(state_space.shape[0])
-    max_int_state_space = np.iinfo(dtype_state_space).max
+    state_space = array_with_smallest_uint_dtype(state_space)
 
     # Create indexer array that maps states to indexes
-    map_state_to_index = create_indexer_for_space(
-        state_space, dtype_state_space, max_int_state_space
-    )
+    map_state_to_index = create_indexer_for_space(state_space)
 
     state_space_dict = {
-        key: state_space[:, i]
+        key: array_with_smallest_uint_dtype(state_space[:, i])
         for i, key in enumerate(states_names_without_exog + exog_states_names)
     }
 
+    exog_state_space = array_with_smallest_uint_dtype(exog_state_space)
+
     return (
         state_space,
         state_space_dict,
@@ -347,9 +346,7 @@ def create_state_choice_space(
             idx += 1
 
     state_choice_space_final = state_choice_space[:idx]
-    map_state_choice_to_index = create_indexer_for_space(
-        state_choice_space_final, dtype_state_choice_space, max_int_state_choice_space
-    )
+    map_state_choice_to_index = create_indexer_for_space(state_choice_space_final)
 
     return (
         state_choice_space_final,
@@ -483,7 +480,7 @@ def add_endog_states(id_endog_state):
     return add_endog_states
 
 
-def create_indexer_for_space(space, dtype_state_space, max_int_state_space):
+def create_indexer_for_space(space):
     """Creates indexer for spaces.
 
     We need to think about which datatype we want to use and what is our invalid number.
@@ -535,8 +532,13 @@ def check_options(options):
     return options
 
 
+def array_with_smallest_uint_dtype(array):
+    """Return array with the smallest unsigned integer dtype."""
+    return array.astype(get_smallest_uint_type(array.max()))
+
+
 def get_smallest_uint_type(n_values):
     uint_types = [np.uint8, np.uint16, np.uint32, np.uint64]
     for dtype in uint_types:
-        if np.iinfo(dtype).max >= n_values:
+        if np.iinfo(dtype).max > n_values:
             return dtype