diff --git a/lib/lrama/grammar/parameterizing_rule_resolver.rb b/lib/lrama/grammar/parameterizing_rule_resolver.rb
index 3392768b..f44ae0f6 100644
--- a/lib/lrama/grammar/parameterizing_rule_resolver.rb
+++ b/lib/lrama/grammar/parameterizing_rule_resolver.rb
@@ -19,12 +19,13 @@ def defined?(name)
       end
 
       def build_rules(token, rule_counter, lhs_tag, user_code, precedence_sym, line)
-        @parameterizing_rule_builders.each do |builder|
-          build_token = builder.build_token(token)
-          @rules = @rules + builder.build_rules(token, build_token, rule_counter, lhs_tag, user_code, precedence_sym, line)
-          @tokens << build_token
-          @term = builder.term
-        end
+        builder = @parameterizing_rule_builders.select { |b| b.name == token.s_value }.last
+        raise "Unknown parameterizing rule #{token.s_value} at line #{token.line}" unless builder
+
+        build_token = builder.build_token(token)
+        @rules = @rules + builder.build_rules(token, build_token, rule_counter, lhs_tag, user_code, precedence_sym, line)
+        @tokens << build_token
+        @term = builder.term
       end
     end
   end
diff --git a/spec/fixtures/parameterizing_rules/user_defined.y b/spec/fixtures/parameterizing_rules/user_defined.y
index ae67a97a..b370f279 100644
--- a/spec/fixtures/parameterizing_rules/user_defined.y
+++ b/spec/fixtures/parameterizing_rules/user_defined.y
@@ -16,6 +16,10 @@ static int yyerror(YYLTYPE *loc, const char *str);
                        | X
                        ;
 
+%rule unused_define(X): /* empty */
+                      | X
+                      ;
+
 %%
 
 program         : defined_option(number) <i>
diff --git a/spec/lrama/parser_spec.rb b/spec/lrama/parser_spec.rb
index ffffde8e..22e47df9 100644
--- a/spec/lrama/parser_spec.rb
+++ b/spec/lrama/parser_spec.rb
@@ -1238,7 +1238,7 @@
             token_code: nil,
             nullable: false,
             precedence_sym: grammar.find_symbol_by_s_value!("YYEOF"),
-            lineno: 21,
+            lineno: 25,
           ),
           Rule.new(
             id: 1,
@@ -1249,7 +1249,7 @@
             token_code: nil,
             nullable: true,
             precedence_sym: nil,
-            lineno: 21,
+            lineno: 25,
           ),
           Rule.new(
             id: 2,
@@ -1259,7 +1259,7 @@
             token_code: nil,
             nullable: true,
             precedence_sym: nil,
-            lineno: 21,
+            lineno: 25,
           ),
           Rule.new(
             id: 3,
@@ -1271,7 +1271,7 @@
             token_code: nil,
             nullable: false,
             precedence_sym: grammar.find_symbol_by_s_value!("number"),
-            lineno: 21,
+            lineno: 25,
           ),
         ])
       end