diff --git a/lib/imbecile/fa.rb b/lib/imbecile/fa.rb
index 489afa7..0909358 100644
--- a/lib/imbecile/fa.rb
+++ b/lib/imbecile/fa.rb
@@ -56,35 +56,6 @@ module Imbecile
         end
     end
 
-    def build_tables
-      transition_table = []
-      state_table = []
-      states = enumerate
-      states.each do |state, id|
-        accepts =
-          if state.accepts.nil?
-            TOKEN_NONE
-          elsif state.accepts.name
-            state.accepts.id
-          else
-            TOKEN_DROP
-          end
-        state_table << {
-          transition_table_index: transition_table.size,
-          n_transitions: state.transitions.size,
-          accepts: accepts,
-        }
-        state.transitions.each do |transition|
-          transition_table << {
-            first: transition.code_point_range.first,
-            last: transition.code_point_range.last,
-            destination: states[transition.destination],
-          }
-        end
-      end
-      [transition_table, state_table]
-    end
-
   end
 
 end
diff --git a/lib/imbecile/lexer/dfa.rb b/lib/imbecile/lexer/dfa.rb
index ab5d3d2..74903f4 100644
--- a/lib/imbecile/lexer/dfa.rb
+++ b/lib/imbecile/lexer/dfa.rb
@@ -22,6 +22,35 @@ module Imbecile
         @start_state = @states[0]
       end
 
+      def build_tables
+        transition_table = []
+        state_table = []
+        states = enumerate
+        states.each do |state, id|
+          accepts =
+            if state.accepts.nil?
+              TOKEN_NONE
+            elsif state.accepts.name
+              state.accepts.id
+            else
+              TOKEN_DROP
+            end
+          state_table << {
+            transition_table_index: transition_table.size,
+            n_transitions: state.transitions.size,
+            accepts: accepts,
+          }
+          state.transitions.each do |transition|
+            transition_table << {
+              first: transition.code_point_range.first,
+              last: transition.code_point_range.last,
+              destination: states[transition.destination],
+            }
+          end
+        end
+        [transition_table, state_table]
+      end
+
       private
 
       def register_nfa_state_set(nfa_state_set)