diff --git a/spec/lib/mastodon/ip_blocks_cli_spec.rb b/spec/lib/mastodon/ip_blocks_cli_spec.rb
new file mode 100644
index 000000000..27c005772
--- /dev/null
+++ b/spec/lib/mastodon/ip_blocks_cli_spec.rb
@@ -0,0 +1,292 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+require 'mastodon/ip_blocks_cli'
+
+RSpec.describe Mastodon::IpBlocksCLI do
+  let(:cli) { described_class.new }
+
+  describe '#add' do
+    let(:ip_list) do
+      [
+        '192.0.2.1',
+        '172.16.0.1',
+        '192.0.2.0/24',
+        '172.16.0.0/16',
+        '10.0.0.0/8',
+        '2001:0db8:85a3:0000:0000:8a2e:0370:7334',
+        'fe80::1',
+        '::1',
+        '2001:0db8::/32',
+        'fe80::/10',
+        '::/128',
+      ]
+    end
+    let(:options) { { severity: 'no_access' } }
+
+    shared_examples 'ip address blocking' do
+      it 'blocks all specified IP addresses' do
+        cli.invoke(:add, ip_list, options)
+
+        blocked_ip_addresses = IpBlock.where(ip: ip_list).pluck(:ip)
+        expected_ip_addresses = ip_list.map { |ip| IPAddr.new(ip) }
+
+        expect(blocked_ip_addresses).to match_array(expected_ip_addresses)
+      end
+
+      it 'sets the severity for all blocked IP addresses' do
+        cli.invoke(:add, ip_list, options)
+
+        blocked_ips_severity = IpBlock.where(ip: ip_list).pluck(:severity).all?(options[:severity])
+
+        expect(blocked_ips_severity).to be(true)
+      end
+
+      it 'displays a success message with a summary' do
+        expect { cli.invoke(:add, ip_list, options) }.to output(
+          a_string_including("Added #{ip_list.size}, skipped 0, failed 0")
+        ).to_stdout
+      end
+    end
+
+    context 'with valid IP addresses' do
+      include_examples 'ip address blocking'
+    end
+
+    context 'when a specified IP address is already blocked' do
+      let!(:blocked_ip) { IpBlock.create(ip: ip_list.last, severity: options[:severity]) }
+
+      it 'skips the already blocked IP address' do
+        allow(IpBlock).to receive(:new).and_call_original
+
+        cli.invoke(:add, ip_list, options)
+
+        expect(IpBlock).to_not have_received(:new).with(ip: ip_list.last)
+      end
+
+      it 'displays the correct summary' do
+        expect { cli.invoke(:add, ip_list, options) }.to output(
+          a_string_including("#{ip_list.last} is already blocked\nAdded #{ip_list.size - 1}, skipped 1, failed 0")
+        ).to_stdout
+      end
+
+      context 'with --force option' do
+        let!(:blocked_ip) { IpBlock.create(ip: ip_list.last, severity: 'no_access') }
+        let(:options) { { severity: 'sign_up_requires_approval', force: true } }
+
+        it 'overwrites the existing IP block record' do
+          expect { cli.invoke(:add, ip_list, options) }
+            .to change { blocked_ip.reload.severity }
+            .from('no_access')
+            .to('sign_up_requires_approval')
+        end
+
+        include_examples 'ip address blocking'
+      end
+    end
+
+    context 'when a specified IP address is invalid' do
+      let(:ip_list) { ['320.15.175.0', '9.5.105.255', '0.0.0.0'] }
+
+      it 'displays the correct summary' do
+        expect { cli.invoke(:add, ip_list, options) }.to output(
+          a_string_including("#{ip_list.first} is invalid\nAdded #{ip_list.size - 1}, skipped 0, failed 1")
+        ).to_stdout
+      end
+    end
+
+    context 'with --comment option' do
+      let(:options) { { severity: 'no_access', comment: 'Spam' } }
+
+      include_examples 'ip address blocking'
+    end
+
+    context 'with --duration option' do
+      let(:options) { { severity: 'no_access', duration: 10.days } }
+
+      include_examples 'ip address blocking'
+    end
+
+    context 'with "sign_up_requires_approval" severity' do
+      let(:options) { { severity: 'sign_up_requires_approval' } }
+
+      include_examples 'ip address blocking'
+    end
+
+    context 'with "sign_up_block" severity' do
+      let(:options) { { severity: 'sign_up_block' } }
+
+      include_examples 'ip address blocking'
+    end
+
+    context 'when a specified IP address fails to be blocked' do
+      let(:ip_address) { '127.0.0.1' }
+      let(:ip_block) { instance_double(IpBlock, ip: ip_address, save: false) }
+
+      before do
+        allow(IpBlock).to receive(:new).and_return(ip_block)
+        allow(ip_block).to receive(:severity=)
+        allow(ip_block).to receive(:expires_in=)
+      end
+
+      it 'displays an error message' do
+        expect { cli.invoke(:add, [ip_address], options) }
+          .to output(
+            a_string_including("#{ip_address} could not be saved")
+          ).to_stdout
+      end
+    end
+
+    context 'when no IP address is provided' do
+      it 'exits with an error message' do
+        expect { cli.add }.to output(
+          a_string_including('No IP(s) given')
+        ).to_stdout
+          .and raise_error(SystemExit)
+      end
+    end
+  end
+
+  describe '#remove' do
+    context 'when removing exact matches' do
+      let(:ip_list) do
+        [
+          '192.0.2.1',
+          '172.16.0.1',
+          '192.0.2.0/24',
+          '172.16.0.0/16',
+          '10.0.0.0/8',
+          '2001:0db8:85a3:0000:0000:8a2e:0370:7334',
+          'fe80::1',
+          '::1',
+          '2001:0db8::/32',
+          'fe80::/10',
+          '::/128',
+        ]
+      end
+
+      before do
+        ip_list.each { |ip| IpBlock.create(ip: ip, severity: :no_access) }
+      end
+
+      it 'removes exact IP blocks' do
+        cli.invoke(:remove, ip_list)
+
+        expect(IpBlock.where(ip: ip_list)).to_not exist
+      end
+
+      it 'displays success message with a summary' do
+        expect { cli.invoke(:remove, ip_list) }.to output(
+          a_string_including("Removed #{ip_list.size}, skipped 0")
+        ).to_stdout
+      end
+    end
+
+    context 'with --force option' do
+      let!(:block1) { IpBlock.create(ip: '192.168.0.0/24', severity: :no_access) }
+      let!(:block2) { IpBlock.create(ip: '10.0.0.0/16', severity: :no_access) }
+      let!(:block3) { IpBlock.create(ip: '172.16.0.0/20', severity: :no_access) }
+      let(:arguments) { ['192.168.0.5', '10.0.1.50'] }
+      let(:options) { { force: true } }
+
+      it 'removes blocks for IP ranges that cover given IP(s)' do
+        cli.invoke(:remove, arguments, options)
+
+        expect(IpBlock.where(id: [block1.id, block2.id])).to_not exist
+      end
+
+      it 'does not remove other IP ranges' do
+        cli.invoke(:remove, arguments, options)
+
+        expect(IpBlock.where(id: block3.id)).to exist
+      end
+    end
+
+    context 'when a specified IP address is not blocked' do
+      let(:unblocked_ip) { '192.0.2.1' }
+
+      it 'skips the IP address' do
+        expect { cli.invoke(:remove, [unblocked_ip]) }.to output(
+          a_string_including("#{unblocked_ip} is not yet blocked")
+        ).to_stdout
+      end
+
+      it 'displays the summary correctly' do
+        expect { cli.invoke(:remove, [unblocked_ip]) }.to output(
+          a_string_including('Removed 0, skipped 1')
+        ).to_stdout
+      end
+    end
+
+    context 'when a specified IP address is invalid' do
+      let(:invalid_ip) { '320.15.175.0' }
+
+      it 'skips the invalid IP address' do
+        expect { cli.invoke(:remove, [invalid_ip]) }.to output(
+          a_string_including("#{invalid_ip} is invalid")
+        ).to_stdout
+      end
+
+      it 'displays the summary correctly' do
+        expect { cli.invoke(:remove, [invalid_ip]) }.to output(
+          a_string_including('Removed 0, skipped 1')
+        ).to_stdout
+      end
+    end
+
+    context 'when no IP address is provided' do
+      it 'exits with an error message' do
+        expect { cli.remove }.to output(
+          a_string_including('No IP(s) given')
+        ).to_stdout
+          .and raise_error(SystemExit)
+      end
+    end
+  end
+
+  describe '#export' do
+    let(:block1) { IpBlock.create(ip: '192.168.0.0/24', severity: :no_access) }
+    let(:block2) { IpBlock.create(ip: '10.0.0.0/16', severity: :no_access) }
+    let(:block3) { IpBlock.create(ip: '127.0.0.1', severity: :sign_up_block) }
+
+    context 'when --format option is set to "plain"' do
+      let(:options) { { format: 'plain' } }
+
+      it 'exports blocked IPs with "no_access" severity in plain format' do
+        expect { cli.invoke(:export, nil, options) }.to output(
+          a_string_including("#{block1.ip}/#{block1.ip.prefix}\n#{block2.ip}/#{block2.ip.prefix}")
+        ).to_stdout
+      end
+
+      it 'does not export bloked IPs with different severities' do
+        expect { cli.invoke(:export, nil, options) }.to_not output(
+          a_string_including("#{block3.ip}/#{block1.ip.prefix}")
+        ).to_stdout
+      end
+    end
+
+    context 'when --format option is set to "nginx"' do
+      let(:options) { { format: 'nginx' } }
+
+      it 'exports blocked IPs with "no_access" severity in plain format' do
+        expect { cli.invoke(:export, nil, options) }.to output(
+          a_string_including("deny #{block1.ip}/#{block1.ip.prefix};\ndeny #{block2.ip}/#{block2.ip.prefix};")
+        ).to_stdout
+      end
+
+      it 'does not export bloked IPs with different severities' do
+        expect { cli.invoke(:export, nil, options) }.to_not output(
+          a_string_including("deny #{block3.ip}/#{block1.ip.prefix};")
+        ).to_stdout
+      end
+    end
+
+    context 'when --format option is not provided' do
+      it 'exports blocked IPs in plain format by default' do
+        expect { cli.export }.to output(
+          a_string_including("#{block1.ip}/#{block1.ip.prefix}\n#{block2.ip}/#{block2.ip.prefix}")
+        ).to_stdout
+      end
+    end
+  end
+end