diff --git a/changelog/change_require_rubocop_ast_1_9.md b/changelog/change_require_rubocop_ast_1_9.md
new file mode 100644
index 00000000000..c775aed2a2d
--- /dev/null
+++ b/changelog/change_require_rubocop_ast_1_9.md
@@ -0,0 +1 @@
+* [#10803](https://github.com/rubocop/rubocop/pull/10803): Require RuboCop AST 1.9.1 or higher. ([@koic][])
diff --git a/lib/rubocop/cop/style/semicolon.rb b/lib/rubocop/cop/style/semicolon.rb
index c0e968b5e3c..9639b782263 100644
--- a/lib/rubocop/cop/style/semicolon.rb
+++ b/lib/rubocop/cop/style/semicolon.rb
@@ -31,7 +31,6 @@ class Semicolon < Base
         extend AutoCorrector
 
         MSG = 'Do not use semicolons to terminate expressions.'
-        REGEXP_DOTS = %i[tDOT2 tDOT3].freeze
 
         def self.autocorrect_incompatible_with
           [Style::SingleLineMethods]
@@ -40,10 +39,6 @@ def self.autocorrect_incompatible_with
         def on_new_investigation
           return if processed_source.blank?
 
-          ast = processed_source.ast
-          @range_nodes = ast.range_type? ? [ast] : []
-          @range_nodes.concat(ast.each_descendant(:irange, :erange).to_a)
-
           check_for_line_terminator_or_opener
         end
 
@@ -95,7 +90,7 @@ def register_semicolon(line, column, after_expression, token_before_semicolon =
               # Prevents becoming one range instance with subsequent line when endless range
               # without parentheses.
               # See: https://github.com/rubocop/rubocop/issues/10791
-              if REGEXP_DOTS.include?(token_before_semicolon&.type)
+              if token_before_semicolon&.regexp_dots?
                 range_node = find_range_node(token_before_semicolon)
                 corrector.wrap(range_node, '(', ')') if range_node
               end
@@ -120,10 +115,18 @@ def find_semicolon_positions(line)
         end
 
         def find_range_node(token_before_semicolon)
-          @range_nodes.detect do |range_node|
+          range_nodes.detect do |range_node|
             range_node.source_range.contains?(token_before_semicolon.pos)
           end
         end
+
+        def range_nodes
+          return @range_nodes if instance_variable_defined?(:@range_nodes)
+
+          ast = processed_source.ast
+          @range_nodes = ast.range_type? ? [ast] : []
+          @range_nodes.concat(ast.each_descendant(:irange, :erange).to_a)
+        end
       end
     end
   end
diff --git a/rubocop.gemspec b/rubocop.gemspec
index 8716f8236fb..d44afb44c90 100644
--- a/rubocop.gemspec
+++ b/rubocop.gemspec
@@ -37,7 +37,7 @@ Gem::Specification.new do |s|
   s.add_runtime_dependency('rainbow', '>= 2.2.2', '< 4.0')
   s.add_runtime_dependency('regexp_parser', '>= 1.8', '< 3.0')
   s.add_runtime_dependency('rexml', '>= 3.2.5', '< 4.0')
-  s.add_runtime_dependency('rubocop-ast', '>= 1.18.0', '< 2.0')
+  s.add_runtime_dependency('rubocop-ast', '>= 1.19.1', '< 2.0')
   s.add_runtime_dependency('ruby-progressbar', '~> 1.7')
   s.add_runtime_dependency('unicode-display_width', '>= 1.4.0', '< 3.0')