diff --git a/bin/whoisrb b/bin/whoisrb
index 9dd7f7bc1..76351776d 100755
--- a/bin/whoisrb
+++ b/bin/whoisrb
@@ -47,7 +47,7 @@ OptionParser.new do |opts|
     exit 1
   end
 
-  if ARGV.size.zero?
+  if ARGV.empty?
     puts opts
     exit 1
   end
diff --git a/lib/whois.rb b/lib/whois.rb
index 63336f0bc..d578e0dc5 100644
--- a/lib/whois.rb
+++ b/lib/whois.rb
@@ -44,7 +44,7 @@ def lookup(object)
     def available?(object)
       unless defined? Whois::Parser
         warn("Whois.available? requires the gem `whois-parser`")
-        return
+        return false
       end
 
       deprecate(%{Whois.available? is deprecated. Call Whois.whois("#{object}").parser.available?})
@@ -61,7 +61,7 @@ def available?(object)
     def registered?(object)
       unless defined? Whois::Parser
         warn("Whois.registered? requires the gem `whois-parser`")
-        return
+        return false
       end
 
       deprecate(%{Whois.registered? is deprecated. Call Whois.whois("#{object}").parser.registered?})
@@ -90,8 +90,8 @@ def deprecate(message = nil, callstack = caller)
     # @private
     def bug!(error, message)
       raise error, message.dup <<
-                   " Please report the issue at" \
-                   " http://github.com/weppos/whois/issues"
+                   " Please report the issue at " \
+                   "http://github.com/weppos/whois/issues"
     end
 
 
diff --git a/lib/whois/record/part.rb b/lib/whois/record/part.rb
index 339159d4c..68b7568b7 100644
--- a/lib/whois/record/part.rb
+++ b/lib/whois/record/part.rb
@@ -26,7 +26,7 @@ class Record
       def initialize(*args)
         if args.first.is_a? Hash
           initialize_with_hash(args.first)
-        elsif args.size.zero?
+        elsif args.empty?
           super
         else
           raise ArgumentError
diff --git a/lib/whois/server/adapters/arin.rb b/lib/whois/server/adapters/arin.rb
index 59107e747..58c2e8324 100644
--- a/lib/whois/server/adapters/arin.rb
+++ b/lib/whois/server/adapters/arin.rb
@@ -44,7 +44,7 @@ def extract_referral(response)
 
           {
             host: Regexp.last_match(1),
-            port: Regexp.last_match(2) ? Regexp.last_match(2).to_i : nil,
+            port: Regexp.last_match(2)&.to_i,
           }
         end
 
diff --git a/spec/whois/record_spec.rb b/spec/whois/record_spec.rb
index 21defdba2..6e4b44d14 100644
--- a/spec/whois/record_spec.rb
+++ b/spec/whois/record_spec.rb
@@ -138,8 +138,8 @@
 
   describe "#match?" do
     it "calls match and checks for match" do
-      expect(subject.match?(/record/)).to eq(true)
-      expect(subject.match?(/nomatch/)).to eq(false)
+      expect(subject.match?(/record/)).to be(true)
+      expect(subject.match?(/nomatch/)).to be(false)
     end
   end