diff --git a/.ameba.yml b/.ameba.yml
new file mode 100644
index 0000000..812b3b2
--- /dev/null
+++ b/.ameba.yml
@@ -0,0 +1,28 @@
+Metrics/CyclomaticComplexity:
+  Excluded:
+    - spec/**/*
+    - src/markd/utils.cr
+    - src/markd/rules/heading.cr
+    - src/markd/rules/list.cr
+    - src/markd/parsers/inline.cr
+    - src/markd/parsers/block.cr
+    - src/markd/renderer.cr
+
+Naming/QueryBoolMethods:
+  Enabled: false
+
+Naming/BlockParameterName:
+  Enabled: false
+
+Style/UnlessElse:
+  Enabled: false
+
+Style/ParenthesesAroundCondition:
+  Enabled: false
+
+Style/NegatedConditionsInUnless:
+  Enabled: false
+
+Lint/NotNil:
+  Excluded:
+    - src/markd/parsers/inline.cr
diff --git a/spec/spec_helper.cr b/spec/spec_helper.cr
index 646e34e..80ffc02 100644
--- a/spec/spec_helper.cr
+++ b/spec/spec_helper.cr
@@ -57,9 +57,6 @@ def assert_example(file, section, index, example, smart, gfm = false)
 end
 
 def extract_spec_tests(file)
-  data = [] of String
-  delimiter = "`" * 32
-
   examples = {} of String => Hash(Int32, Hash(String, String))
 
   current_section = 0
diff --git a/src/markd/node.cr b/src/markd/node.cr
index 1f4ee80..c43c061 100644
--- a/src/markd/node.cr
+++ b/src/markd/node.cr
@@ -156,7 +156,7 @@ module Markd
           end
         elsif current == @root
           @current = nil
-        elsif nxt = current.next?
+        elsif current.next?
           @current = current.next?
           @entering = true
         else
diff --git a/src/markd/parsers/inline.cr b/src/markd/parsers/inline.cr
index bc6da59..5f39fb9 100644
--- a/src/markd/parsers/inline.cr
+++ b/src/markd/parsers/inline.cr
@@ -750,7 +750,7 @@ module Markd::Parser
         }
       end
 
-      return @pos - startpos
+      @pos - startpos
     end
 
     private def space_at_end_of_line?
@@ -765,7 +765,8 @@ module Markd::Parser
       else
         return false
       end
-      return true
+
+      true
     end
 
     # Parse zero or more space characters, including at most one newline
@@ -781,7 +782,7 @@ module Markd::Parser
         @pos += 1
       end
 
-      return true
+      true
     end
 
     private def match(regex : Regex) : String?
diff --git a/src/markd/renderers/html_renderer.cr b/src/markd/renderers/html_renderer.cr
index 4d8505b..fdaa019 100644
--- a/src/markd/renderers/html_renderer.cr
+++ b/src/markd/renderers/html_renderer.cr
@@ -222,7 +222,7 @@ module Markd
       @last_output = ">"
     end
 
-    private def tag(name : String, attrs = nil)
+    private def tag(name : String, attrs = nil, &)
       tag(name, attrs)
       yield
       tag(name, end_tag: true)
diff --git a/src/markd/utils.cr b/src/markd/utils.cr
index deb4066..cd15719 100644
--- a/src/markd/utils.cr
+++ b/src/markd/utils.cr
@@ -2,7 +2,7 @@ require "json"
 
 module Markd
   module Utils
-    def self.timer(label : String, measure_time? : Bool)
+    def self.timer(label : String, measure_time? : Bool, &)
       return yield unless measure_time?
 
       start_time = Time.utc
@@ -14,7 +14,7 @@ module Markd
     DECODE_ENTITIES_REGEX = Regex.new("\\\\" + Rule::ESCAPABLE_STRING, Regex::Options::IGNORE_CASE)
 
     def self.decode_entities_string(text : String) : String
-      HTML.decode_entities(text).gsub(DECODE_ENTITIES_REGEX) { |text| text[1].to_s }
+      HTML.decode_entities(text).gsub(DECODE_ENTITIES_REGEX, &.[1].to_s)
     end
   end
 end