diff --git a/.ameba.yml b/.ameba.yml
new file mode 100644
index 0000000..0c35944
--- /dev/null
+++ b/.ameba.yml
@@ -0,0 +1,9 @@
+Lint/NotNil:
+  Enabled: false
+Lint/MissingBlockArgument:
+  Enabled: true
+Documentation/DocumentationAdmonition:
+  Enabled: false
+Metrics/CyclomaticComplexity:
+  Enabled: false
+
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index d1a9254..7074739 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -18,7 +18,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
       - name: Download source
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
       - name: Install Crystal
         uses: crystal-lang/install-crystal@v1
       - name: Check formatting
@@ -27,4 +27,14 @@ jobs:
         run: shards update
       - name: Run tests
         run: crystal spec --order=random
-        if: matrix.os == 'ubuntu-latest'
+  ameba:
+    strategy:
+      fail-fast: false
+    runs-on: ubuntu-latest
+    steps:
+      - name: Download source
+        uses: actions/checkout@v4
+      - name: Run ameba linter
+        uses: crystal-ameba/github-action@v0.12.0
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
diff --git a/spec/integration/integration_spec.cr b/spec/integration/integration_spec.cr
index acbebc8..d66071c 100644
--- a/spec/integration/integration_spec.cr
+++ b/spec/integration/integration_spec.cr
@@ -25,7 +25,7 @@ class GoldenTest
 
   private def context : Liquid::Context
     vars = @context.as_h?
-    raise "Bad context: #{@context.to_s}" if vars.nil?
+    raise "Bad context: #{@context}" if vars.nil?
 
     # Golden liquid run ruby tests with `render!`, that raises an exception on first error, this is the strict behavior
     # of liquid crystal.
diff --git a/src/liquid/blank.cr b/src/liquid/blank.cr
index f51cafe..0084183 100644
--- a/src/liquid/blank.cr
+++ b/src/liquid/blank.cr
@@ -2,15 +2,15 @@ require "./drop"
 
 module Liquid
   class Blank < Drop
-    def ==(str : String)
-      str.empty?
+    def ==(other : String)
+      other.empty?
     end
 
-    def ==(array : Array)
-      array.empty?
+    def ==(other : Array)
+      other.empty?
     end
 
-    def ==(_nil : Nil)
+    def ==(other : Nil)
       true
     end
 
diff --git a/src/liquid/blocks/for.cr b/src/liquid/blocks/for.cr
index d92f11e..317691f 100644
--- a/src/liquid/blocks/for.cr
+++ b/src/liquid/blocks/for.cr
@@ -31,7 +31,7 @@ module Liquid::Block
         @loop_var = gmatch["var"]
         @loop_over = if rmatch = gmatch["range"].match(RANGE)
                        rmatch["start"].to_i..rmatch["end"].to_i
-                     elsif (rmatch = gmatch["range"].match VARNAME)
+                     elsif rmatch = gmatch["range"].match VARNAME
                        rmatch["varname"]
                      else
                        raise SyntaxError.new("Invalid for node: #{content}.")
diff --git a/src/liquid/blocks/include.cr b/src/liquid/blocks/include.cr
index d86827e..355d1a8 100644
--- a/src/liquid/blocks/include.cr
+++ b/src/liquid/blocks/include.cr
@@ -26,7 +26,7 @@ module Liquid::Block
           varname = File.basename(@template_name, File.extname(@template_name))
           @template_vars[varname] = Expression.new match["value"]
         elsif groups = content.scan INCLUDE_VARS
-          groups.each do |group|
+          groups.each do |_|
             next if groups.empty?
 
             groups.each do |group|
diff --git a/src/liquid/drop.cr b/src/liquid/drop.cr
index 69d7c24..c0b18f7 100644
--- a/src/liquid/drop.cr
+++ b/src/liquid/drop.cr
@@ -40,19 +40,19 @@ module Liquid
 end
 
 class String
-  def ==(any : Liquid::Drop)
-    any == self
+  def ==(other : Liquid::Drop)
+    other == self
   end
 end
 
 struct Nil
-  def ==(any : Liquid::Drop)
-    any == self
+  def ==(other : Liquid::Drop)
+    other == self
   end
 end
 
 class Array
-  def ==(any : Liquid::Drop)
-    any == self
+  def ==(other : Liquid::Drop)
+    other == self
   end
 end
diff --git a/src/liquid/expression.cr b/src/liquid/expression.cr
index c4b016b..bd9cb5f 100644
--- a/src/liquid/expression.cr
+++ b/src/liquid/expression.cr
@@ -155,7 +155,7 @@ module Liquid
     private def apply_filters(ctx : Context, operand : Any, filter_stack : Stack?) : Any
       return operand if filter_stack.nil?
 
-      while filter_stack.any?
+      while !filter_stack.empty?
         item = filter_stack.shift
         return expression_error(ctx, "Expected a filter, got #{item}.") if !item.is_a?(Operator) || !item.filter?
 
@@ -184,7 +184,7 @@ module Liquid
       filter_args = ctx.filter_args
       filter_options = ctx.filter_options
 
-      while stack.any?
+      while !stack.empty?
         item = stack.first
         return if item.is_a?(Operator) && item.filter?
 
@@ -218,7 +218,7 @@ module Liquid
       raw = obj.raw
       return call_drop_method(ctx, raw, method) if raw.is_a?(Drop)
       return call_hash_method(ctx, raw, method) if raw.is_a?(Hash)
-      return call_nil_method(ctx, method) if raw.is_a?(Nil)
+      return call_nil_method(ctx, method) if raw.nil?
 
       return expression_error(ctx, "Tried to call ##{method} on a #{raw.class.name}.") if !raw.responds_to?(:size)
 
diff --git a/src/liquid/filters/abs.cr b/src/liquid/filters/abs.cr
index f007673..7cc3eaa 100644
--- a/src/liquid/filters/abs.cr
+++ b/src/liquid/filters/abs.cr
@@ -16,7 +16,7 @@ module Liquid::Filters
     extend Filter
 
     def self.filter(data : Any, args : Array(Any), options : Hash(String, Any)) : Any
-      raise FilterArgumentException.new("Unexpected argument for abs filter") if args && args.any?
+      raise FilterArgumentException.new("Unexpected argument for abs filter") unless args.empty?
 
       if data.raw.is_a? Number
         Any.new data.raw.as(Number).abs
diff --git a/src/liquid/filters/arg_test.cr b/src/liquid/filters/arg_test.cr
index 0e62a5b..c038c7e 100644
--- a/src/liquid/filters/arg_test.cr
+++ b/src/liquid/filters/arg_test.cr
@@ -5,7 +5,7 @@ module Liquid::Filters
     extend Filter
 
     def self.filter(data : Any, args : Array(Any), options : Hash(String, Any)) : Any
-      if (a = args)
+      if a = args
         Any.new(a.map(&.to_s).join(", "))
       else
         Any.new(nil)
diff --git a/src/liquid/filters/capitalize.cr b/src/liquid/filters/capitalize.cr
index 3e5168b..9e09600 100644
--- a/src/liquid/filters/capitalize.cr
+++ b/src/liquid/filters/capitalize.cr
@@ -20,7 +20,7 @@ module Liquid::Filters
     extend Filter
 
     def self.filter(data : Any, args : Array(Any), options : Hash(String, Any)) : Any
-      raise FilterArgumentException.new("Unexpected argument for capitalize filter") if args && args.any?
+      raise FilterArgumentException.new("Unexpected argument for capitalize filter") unless args.empty?
 
       raw = data.raw
       if raw.is_a?(String)
diff --git a/src/liquid/filters/ceil.cr b/src/liquid/filters/ceil.cr
index ca81a3c..9278167 100644
--- a/src/liquid/filters/ceil.cr
+++ b/src/liquid/filters/ceil.cr
@@ -31,7 +31,7 @@ module Liquid::Filters
     extend Filter
 
     def self.filter(data : Any, args : Array(Any), options : Hash(String, Any)) : Any
-      raise FilterArgumentException.new("Unexpected argument for ceil filter") if args && args.any?
+      raise FilterArgumentException.new("Unexpected argument for ceil filter") unless args.empty?
 
       if (raw = data.raw) && raw.is_a? Number
         Any.new(raw.ceil.to_i)
diff --git a/src/liquid/filters/date.cr b/src/liquid/filters/date.cr
index 6df80eb..86a4f2c 100644
--- a/src/liquid/filters/date.cr
+++ b/src/liquid/filters/date.cr
@@ -31,13 +31,13 @@ module Liquid::Filters
     def self.filter(data : Any, args : Array(Any), options : Hash(String, Any)) : Any
       raise FilterArgumentException.new "date filter require an argument" unless args && args.size == 1
 
-      format = if (arg = args.first.as_s?)
+      format = if arg = args.first.as_s?
                  arg
                else
                  raise FilterArgumentException.new "First argument of date filter should be a string"
                end
 
-      if (time = data.as_t?)
+      if time = data.as_t?
         Any.new time.to_s format
       elsif (d = data.as_s?) && d == "now"
         Any.new Time.utc.to_s format
diff --git a/src/liquid/filters/downcase.cr b/src/liquid/filters/downcase.cr
index 1c2fe56..38bbfbe 100644
--- a/src/liquid/filters/downcase.cr
+++ b/src/liquid/filters/downcase.cr
@@ -22,7 +22,7 @@ module Liquid::Filters
     extend Filter
 
     def self.filter(data : Any, args : Array(Any), options : Hash(String, Any)) : Any
-      raise FilterArgumentException.new("downcase filter expects no arguments.") if args.any?
+      raise FilterArgumentException.new("downcase filter expects no arguments.") unless args.empty?
 
       raw = data.raw
       if raw.responds_to?(:downcase)
diff --git a/src/liquid/filters/floor.cr b/src/liquid/filters/floor.cr
index 37544f8..600272c 100644
--- a/src/liquid/filters/floor.cr
+++ b/src/liquid/filters/floor.cr
@@ -14,7 +14,7 @@ module Liquid::Filters
     extend Filter
 
     def self.filter(data : Any, args : Array(Any), options : Hash(String, Any)) : Any
-      raise FilterArgumentException.new("Unexpected argument for floor filter") if args && args.any?
+      raise FilterArgumentException.new("Unexpected argument for floor filter") unless args.empty?
 
       if (raw = data.raw) && raw.is_a? Number
         Any.new(raw.floor.to_i)
diff --git a/src/liquid/filters/lstrip.cr b/src/liquid/filters/lstrip.cr
index a6ed4c8..4c438ea 100644
--- a/src/liquid/filters/lstrip.cr
+++ b/src/liquid/filters/lstrip.cr
@@ -5,7 +5,7 @@ module Liquid::Filters
     extend Filter
 
     def self.filter(data : Any, args : Array(Any), options : Hash(String, Any)) : Any
-      if (str = data.as_s?)
+      if str = data.as_s?
         Any.new str.lstrip
       else
         data
diff --git a/src/liquid/filters/map.cr b/src/liquid/filters/map.cr
index 06b149c..673d9ee 100644
--- a/src/liquid/filters/map.cr
+++ b/src/liquid/filters/map.cr
@@ -14,7 +14,7 @@ module Liquid::Filters
       raise FilterArgumentException.new "map filter expects argument to be a string" unless args.first.raw.is_a?(String)
 
       if (raw = data.raw) && raw.is_a?(Array) && (first = args.first?)
-        result = raw.compact_map { |r| self.responds_to(r, first.as_s) }
+        result = raw.compact_map { |obj| self.responds_to(obj, first.as_s) }
         if result.empty?
           data
         else
diff --git a/src/liquid/filters/rstrip.cr b/src/liquid/filters/rstrip.cr
index 7bd61bf..6f5a9f5 100644
--- a/src/liquid/filters/rstrip.cr
+++ b/src/liquid/filters/rstrip.cr
@@ -5,7 +5,7 @@ module Liquid::Filters
     extend Filter
 
     def self.filter(data : Any, args : Array(Any), options : Hash(String, Any)) : Any
-      if (str = data.as_s?)
+      if str = data.as_s?
         Any.new str.rstrip
       else
         data
diff --git a/src/liquid/filters/split.cr b/src/liquid/filters/split.cr
index 2fffc36..f56dcef 100644
--- a/src/liquid/filters/split.cr
+++ b/src/liquid/filters/split.cr
@@ -32,7 +32,7 @@ module Liquid::Filters
       return Any.new(nil) if raw_data.nil?
 
       if raw_data.responds_to?(:split)
-        array = raw_data.split(arg).map { |s| Any.new(s) }
+        array = raw_data.split(arg).map { |obj| Any.new(obj) }
         Any.new(array)
       else
         Any{data}
diff --git a/src/liquid/filters/strip.cr b/src/liquid/filters/strip.cr
index d29f383..512cabf 100644
--- a/src/liquid/filters/strip.cr
+++ b/src/liquid/filters/strip.cr
@@ -5,7 +5,7 @@ module Liquid::Filters
     extend Filter
 
     def self.filter(data : Any, args : Array(Any), options : Hash(String, Any)?) : Any
-      if (str = data.as_s?)
+      if str = data.as_s?
         Any.new str.strip
       else
         data
diff --git a/src/liquid/filters/upcase.cr b/src/liquid/filters/upcase.cr
index 4a6958e..0627a24 100644
--- a/src/liquid/filters/upcase.cr
+++ b/src/liquid/filters/upcase.cr
@@ -13,7 +13,7 @@ module Liquid::Filters
     extend Filter
 
     def self.filter(data : Any, args : Array(Any), options : Hash(String, Any)?) : Any
-      raise FilterArgumentException.new("upcase filter expects no arguments.") if args.any?
+      raise FilterArgumentException.new("upcase filter expects no arguments.") unless args.empty?
 
       raw = data.raw
       if raw.responds_to?(:upcase)
diff --git a/src/liquid/match_visitor.cr b/src/liquid/match_visitor.cr
index e3bed94..b5fc676 100644
--- a/src/liquid/match_visitor.cr
+++ b/src/liquid/match_visitor.cr
@@ -3,15 +3,15 @@ require "./blocks"
 module Liquid
   class MatchVisitor < Visitor
     def visit(node : Node) : String
-      return node.children.map { |e| self.visit e }.join
+      node.children.map { |e| self.visit e }.join
     end
 
     def visit(node : Block::RawNode) : String
-      return node.content
+      node.content
     end
 
     def visit(node : ExpressionNode)
-      return ".*"
+      ".*"
     end
 
     def visit(node : Conditional) : String
@@ -29,7 +29,7 @@ module Liquid
         child_nodes << ""
       end
 
-      return "(#{child_nodes.join("|")})"
+      "(#{child_nodes.join("|")})"
     end
 
     def visit(node : Case)
@@ -47,13 +47,13 @@ module Liquid
         child_nodes << ""
       end
 
-      return "(#{child_nodes.join("|")})"
+      "(#{child_nodes.join("|")})"
     end
 
     def visit(node : For)
       child_nodes = node.children.map { |e| self.visit e }
 
-      return "(#{child_nodes.join})*"
+      "(#{child_nodes.join})*"
     end
   end
 end
diff --git a/src/liquid/template.cr b/src/liquid/template.cr
index 11bd2e7..1c39c9e 100644
--- a/src/liquid/template.cr
+++ b/src/liquid/template.cr
@@ -29,7 +29,7 @@ module Liquid
       match_string = visitor.visit @root
       match_regex = /^#{match_string}$/
 
-      return match_regex.matches?(target_string)
+      match_regex.matches?(target_string)
     end
 
     def render(data, io : IO) : Nil