diff --git a/colorls.gemspec b/colorls.gemspec
index 8bf8d0a..484f7b2 100644
--- a/colorls.gemspec
+++ b/colorls.gemspec
@@ -72,7 +72,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'diffy', '3.4.2'
   spec.add_development_dependency 'rake', '~> 13'
   spec.add_development_dependency 'rdoc', '~> 6.1'
-  spec.add_development_dependency 'ronn', '~> 0'
+  spec.add_development_dependency 'ronn-ng', '~> 0'
   spec.add_development_dependency 'rspec', '~> 3.7'
   spec.add_development_dependency 'rspec-its', '~> 1.2'
   spec.add_development_dependency 'rubocop', '~> 1.50.1'
diff --git a/lib/colorls/core.rb b/lib/colorls/core.rb
index f5f7707..2027cda 100644
--- a/lib/colorls/core.rb
+++ b/lib/colorls/core.rb
@@ -260,7 +260,7 @@ module ColorLS
 
     def size_info(filesize)
       filesize = Filesize.new(filesize)
-      size = @show_human_readable_size ? filesize.pretty : filesize.to_s
+      size = @show_human_readable_size ? filesize.pretty(precision: 0) : filesize.to_s('B', precision: 0)
       size = size.split
       size = justify_size_info(size)
       return size.colorize(@colors[:file_large])  if filesize >= 512 * (1024 ** 2)
@@ -280,7 +280,7 @@ module ColorLS
     end
 
     def justify_size_info(size)
-      size_num = size[0][0..-4].rjust(chars_for_size, ' ')
+      size_num = size[0].rjust(chars_for_size, ' ')
       size_unit = @show_human_readable_size ? size[1].ljust(3, ' ') : size[1]
       "#{size_num} #{size_unit}"
     end
diff --git a/spec/color_ls/flags_spec.rb b/spec/color_ls/flags_spec.rb
index 746df84..a730b82 100644
--- a/spec/color_ls/flags_spec.rb
+++ b/spec/color_ls/flags_spec.rb
@@ -65,7 +65,7 @@ RSpec.describe ColorLS::Flags do
     it 'displays multiple files per line' do
       allow($stdout).to receive(:tty?).and_return(true)
 
-      expect { subject }.not_to output(/(.*\n){4}/).to_stdout
+      expect { subject }.not_to output(/(.*\n){7}/).to_stdout
     end
 
     it('does not display ./ or ../')           { expect { subject }.not_to output(%r(\.{1,2}/)).to_stdout }
@@ -103,6 +103,14 @@ RSpec.describe ColorLS::Flags do
     let(:args) { ['--long', FIXTURES] }
 
     it('lists file info') { expect { subject }.to output(/((r|-).*(w|-).*(x|-).*){3}/).to_stdout }
+
+    it 'rounds up file size to nearest MiB' do
+      expect { subject }.to output(/2 MiB[^\n]* 20kb-less-than-2mb\.txt/).to_stdout
+    end
+
+    it 'rounds down file size to nearest MiB' do
+      expect { subject }.to output(/1 MiB[^\n]* 20kb-more-than-1mb\.txt/).to_stdout
+    end
   end
 
   context 'with --long flag for `a.txt`' do
@@ -347,7 +355,7 @@ RSpec.describe ColorLS::Flags do
     let(:args) { ['--report', '--report=long', FIXTURES] }
 
     it 'shows a report with recognized and unrecognized files' do
-      expect { subject }.to output(/Recognized files\s+: 4\n.+Unrecognized files\s+: 3/).to_stdout
+      expect { subject }.to output(/Recognized files\s+: 6\n.+Unrecognized files\s+: 3/).to_stdout
     end
   end
 
diff --git a/spec/fixtures/20kb-less-than-2mb.txt b/spec/fixtures/20kb-less-than-2mb.txt
new file mode 100644
index 0000000..d54c570
Binary files /dev/null and b/spec/fixtures/20kb-less-than-2mb.txt differ
diff --git a/spec/fixtures/20kb-more-than-1mb.txt b/spec/fixtures/20kb-more-than-1mb.txt
new file mode 100644
index 0000000..c9b4e1f
Binary files /dev/null and b/spec/fixtures/20kb-more-than-1mb.txt differ