diff --git a/.ameba.yml b/.ameba.yml
index 4a61a73..11462c5 100644
--- a/.ameba.yml
+++ b/.ameba.yml
@@ -1,5 +1,5 @@
 # This configuration file was generated by `ameba --gen-config`
-# on 2024-08-04 23:09:09 UTC using Ameba version 1.6.1.
+# on 2024-08-12 22:00:49 UTC using Ameba version 1.6.1.
 # The point is for the user to remove these configuration records
 # one by one as the reported problems are removed from the code base.
 
@@ -9,7 +9,7 @@ Documentation/DocumentationAdmonition:
   Description: Reports documentation admonitions
   Timezone: UTC
   Excluded:
-  - src/tartrazine.cr
+  - src/lexer.cr
   - src/actions.cr
   Admonitions:
   - TODO
@@ -17,3 +17,105 @@ Documentation/DocumentationAdmonition:
   - BUG
   Enabled: true
   Severity: Warning
+
+# Problems found: 22
+# Run `ameba --only Lint/MissingBlockArgument` for details
+Lint/MissingBlockArgument:
+  Description: Disallows yielding method definitions without block argument
+  Excluded:
+  - pygments/tests/examplefiles/cr/test.cr
+  Enabled: true
+  Severity: Warning
+
+# Problems found: 1
+# Run `ameba --only Lint/NotNil` for details
+Lint/NotNil:
+  Description: Identifies usage of `not_nil!` calls
+  Excluded:
+  - pygments/tests/examplefiles/cr/test.cr
+  Enabled: true
+  Severity: Warning
+
+# Problems found: 34
+# Run `ameba --only Lint/ShadowingOuterLocalVar` for details
+Lint/ShadowingOuterLocalVar:
+  Description: Disallows the usage of the same name as outer local variables for block
+    or proc arguments
+  Excluded:
+  - pygments/tests/examplefiles/cr/test.cr
+  Enabled: true
+  Severity: Warning
+
+# Problems found: 1
+# Run `ameba --only Lint/UnreachableCode` for details
+Lint/UnreachableCode:
+  Description: Reports unreachable code
+  Excluded:
+  - pygments/tests/examplefiles/cr/test.cr
+  Enabled: true
+  Severity: Warning
+
+# Problems found: 6
+# Run `ameba --only Lint/UselessAssign` for details
+Lint/UselessAssign:
+  Description: Disallows useless variable assignments
+  ExcludeTypeDeclarations: false
+  Excluded:
+  - pygments/tests/examplefiles/cr/test.cr
+  Enabled: true
+  Severity: Warning
+
+# Problems found: 3
+# Run `ameba --only Naming/BlockParameterName` for details
+Naming/BlockParameterName:
+  Description: Disallows non-descriptive block parameter names
+  MinNameLength: 3
+  AllowNamesEndingInNumbers: true
+  Excluded:
+  - pygments/tests/examplefiles/cr/test.cr
+  AllowedNames:
+  - _
+  - e
+  - i
+  - j
+  - k
+  - v
+  - x
+  - y
+  - ex
+  - io
+  - ws
+  - op
+  - tx
+  - id
+  - ip
+  - k1
+  - k2
+  - v1
+  - v2
+  ForbiddenNames: []
+  Enabled: true
+  Severity: Convention
+
+# Problems found: 1
+# Run `ameba --only Naming/RescuedExceptionsVariableName` for details
+Naming/RescuedExceptionsVariableName:
+  Description: Makes sure that rescued exceptions variables are named as expected
+  Excluded:
+  - pygments/tests/examplefiles/cr/test.cr
+  AllowedNames:
+  - e
+  - ex
+  - exception
+  - error
+  Enabled: true
+  Severity: Convention
+
+# Problems found: 6
+# Run `ameba --only Naming/TypeNames` for details
+Naming/TypeNames:
+  Description: Enforces type names in camelcase manner
+  Excluded:
+  - pygments/tests/examplefiles/cr/test.cr
+  Enabled: true
+  Severity: Convention
diff --git a/src/rules.cr b/src/rules.cr
index 4259505..1f4a7eb 100644
--- a/src/rules.cr
+++ b/src/rules.cr
@@ -11,7 +11,7 @@ module Tartrazine
   # This rule matches via a regex pattern
 
   class Rule
-    property pattern : Regex = Re2.new ""
+    property pattern : Regex = Regex.new ""
     property actions : Array(Action) = [] of Action
     property xml : String = "foo"
 
@@ -33,12 +33,15 @@ module Tartrazine
 
     def initialize(node : XML::Node, multiline, dotall, ignorecase)
       @xml = node.to_s
-      @pattern = Re2.new(
-        node["pattern"],
-        multiline,
-        dotall,
-        ignorecase,
-        anchored: true)
+      pattern = node["pattern"]
+      flags = Regex::Options::ANCHORED
+      # MULTILINE implies DOTALL which we don't want, so we
+      # use in-pattern flag (?m) instead
+      # flags |= Regex::Options::MULTILINE if multiline
+      pattern = "(?m)" + pattern if multiline
+      flags |= Regex::Options::DOTALL if dotall
+      flags |= Regex::Options::IGNORE_CASE if ignorecase
+      @pattern = Regex.new(pattern, flags)
       add_actions(node)
     end
 
@@ -90,25 +93,4 @@ module Tartrazine
       add_actions(node)
     end
   end
-
-  # This is a hack to workaround that Crystal seems to disallow
-  # having regexes multiline but not dot_all
-  class Re2 < Regex
-    @source = "fa"
-    @options = Regex::Options::None
-    @jit = true
-
-    def initialize(pattern : String, multiline = false, dotall = false, ignorecase = false, anchored = false)
-      flags = LibPCRE2::UTF | LibPCRE2::DUPNAMES |
-              LibPCRE2::UCP
-      flags |= LibPCRE2::MULTILINE if multiline
-      flags |= LibPCRE2::DOTALL if dotall
-      flags |= LibPCRE2::CASELESS if ignorecase
-      flags |= LibPCRE2::ANCHORED if anchored
-      flags |= LibPCRE2::NO_UTF_CHECK
-      @re = Regex::PCRE2.compile(pattern, flags) do |error_message|
-        raise Exception.new(error_message)
-      end
-    end
-  end
 end