diff --git a/.gitattributes b/.gitattributes
index 22aac70..8c85471 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -4,7 +4,6 @@
 /LICENSE export-ignore
 /Makefile export-ignore
 /README.md export-ignore
-/phpmd.xml export-ignore
 /phpunit.xml export-ignore
 /phpstan.neon.dist export-ignore
 /infection.json.dist export-ignore
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
new file mode 100644
index 0000000..f0ce8fc
--- /dev/null
+++ b/.github/dependabot.yml
@@ -0,0 +1,31 @@
+version: 2
+
+updates:
+  - package-ecosystem: "composer"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    open-pull-requests-limit: 0
+    labels:
+      - "php"
+      - "security"
+      - "dependencies"
+    groups:
+      php-security:
+        applies-to: security-updates
+        patterns:
+          - "*"
+
+  - package-ecosystem: "github-actions"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    commit-message:
+      prefix: "build"
+    labels:
+      - "dependencies"
+      - "github-actions"
+    groups:
+      github-actions:
+        patterns:
+          - "*"
diff --git a/.github/workflows/auto-assign.yml b/.github/workflows/auto-assign.yml
index a17e92e..f37e91f 100644
--- a/.github/workflows/auto-assign.yml
+++ b/.github/workflows/auto-assign.yml
@@ -18,7 +18,7 @@ jobs:
       - name: Assign issues and pull requests
         uses: gustavofreze/auto-assign@2.0.0
         with:
-          assignees: '${{ secrets.ASSIGNEES }}'
+          assignees: '${{ vars.ASSIGNEES }}'
           github_token: '${{ secrets.GITHUB_TOKEN }}'
           allow_self_assign: 'true'
           allow_no_assignees: 'true'
diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 358ac92..e898dc1 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -7,24 +7,59 @@ permissions:
   contents: read
 
 env:
-  PHP_VERSION: '8.3'
+  PHP_VERSION: '8.5'
 
 jobs:
+  build:
+    name: Build
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v6
+
+      - name: Configure PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ env.PHP_VERSION }}
+          extensions: bcmath
+          tools: composer:2
+
+      - name: Validate composer.json
+        run: composer validate --no-interaction
+
+      - name: Install dependencies
+        run: composer install --no-progress --optimize-autoloader --prefer-dist --no-interaction
+
+      - name: Upload vendor and composer.lock as artifact
+        uses: actions/upload-artifact@v6
+        with:
+          name: vendor-artifact
+          path: |
+            vendor
+            composer.lock
+
   auto-review:
     name: Auto review
     runs-on: ubuntu-latest
+    needs: build
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
       - name: Configure PHP
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ env.PHP_VERSION }}
+          extensions: bcmath
+          tools: composer:2
 
-      - name: Install dependencies
-        run: composer update --no-progress --optimize-autoloader
+      - name: Download vendor artifact from build
+        uses: actions/download-artifact@v7
+        with:
+          name: vendor-artifact
+          path: .
 
       - name: Run review
         run: composer review
@@ -32,18 +67,24 @@ jobs:
   tests:
     name: Tests
     runs-on: ubuntu-latest
+    needs: auto-review
 
     steps:
       - name: Checkout
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
 
-      - name: Use PHP ${{ env.PHP_VERSION }}
+      - name: Configure PHP
         uses: shivammathur/setup-php@v2
         with:
           php-version: ${{ env.PHP_VERSION }}
+          extensions: bcmath
+          tools: composer:2
 
-      - name: Install dependencies
-        run: composer update --no-progress --optimize-autoloader
+      - name: Download vendor artifact from build
+        uses: actions/download-artifact@v7
+        with:
+          name: vendor-artifact
+          path: .
 
       - name: Run tests
         run: composer tests
diff --git a/.github/workflows/codeql.yml b/.github/workflows/codeql.yml
new file mode 100644
index 0000000..4c6d7f7
--- /dev/null
+++ b/.github/workflows/codeql.yml
@@ -0,0 +1,35 @@
+name: Security checks
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+  schedule:
+    - cron: "0 0 * * *"
+
+permissions:
+  actions: read
+  contents: read
+  security-events: write
+
+jobs:
+  analyze:
+    name: Analyze
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        language: [ "actions" ]
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v6
+
+      - name: Initialize CodeQL
+        uses: github/codeql-action/init@v4
+        with:
+          languages: ${{ matrix.language }}
+
+      - name: Perform CodeQL analysis
+        uses: github/codeql-action/analyze@v4
diff --git a/.gitignore b/.gitignore
index 1cb9b22..42b841a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,7 +1,7 @@
 .idea
+
 vendor
 report
-.phpunit.cache
+.phpunit.*
 
-composer.lock
-.phpunit.result.cache
\ No newline at end of file
+*.lock
diff --git a/Makefile b/Makefile
index 96ccd27..ef9a884 100644
--- a/Makefile
+++ b/Makefile
@@ -1,9 +1,4 @@
-ifeq ($(OS),Windows_NT)
-    PWD := $(shell cd)
-else
-    PWD := $(shell pwd -L)
-endif
-
+PWD := $(CURDIR)
 ARCH := $(shell uname -m)
 PLATFORM :=
 
@@ -11,28 +6,63 @@ ifeq ($(ARCH),arm64)
     PLATFORM := --platform=linux/amd64
 endif
 
-DOCKER_RUN = docker run ${PLATFORM} --rm -it --net=host -v ${PWD}:/app -w /app gustavofreze/php:8.3
+DOCKER_RUN = docker run ${PLATFORM} --rm -it --net=host -v ${PWD}:/app -w /app gustavofreze/php:8.5-alpine
 
-.PHONY: configure test test-file test-no-coverage review show-reports clean
+RESET := \033[0m
+GREEN := \033[0;32m
+YELLOW := \033[0;33m
 
-configure:
+.DEFAULT_GOAL := help
+
+.PHONY: configure
+configure: ## Configure development environment
 	@${DOCKER_RUN} composer update --optimize-autoloader
 
-test:
+.PHONY: test
+test: ## Run all tests with coverage
 	@${DOCKER_RUN} composer tests
 
-test-file:
+.PHONY: test-file
+test-file: ## Run tests for a specific file (usage: make test-file FILE=path/to/file)
 	@${DOCKER_RUN} composer test-file ${FILE}
 
-test-no-coverage:
+.PHONY: test-no-coverage
+test-no-coverage: ## Run all tests without coverage
 	@${DOCKER_RUN} composer tests-no-coverage
 
-review:
+.PHONY: review
+review: ## Run static code analysis
 	@${DOCKER_RUN} composer review
 
-show-reports:
+.PHONY: show-reports
+show-reports: ## Open static analysis reports (e.g., coverage, lints) in the browser
 	@sensible-browser report/coverage/coverage-html/index.html report/coverage/mutation-report.html
 
-clean:
+.PHONY: clean
+clean: ## Remove dependencies and generated artifacts
 	@sudo chown -R ${USER}:${USER} ${PWD}
 	@rm -rf report vendor .phpunit.cache *.lock
+
+.PHONY: help
+help:  ## Display this help message
+	@echo "Usage: make [target]"
+	@echo ""
+	@echo "$$(printf '$(GREEN)')Setup$$(printf '$(RESET)')"
+	@grep -E '^(configure):.*?## .*$$' $(MAKEFILE_LIST) \
+		| awk 'BEGIN {FS = ":.*? ## "}; {printf "$(YELLOW)%-25s$(RESET) %s\n", $$1, $$2}'
+	@echo ""
+	@echo "$$(printf '$(GREEN)')Testing$$(printf '$(RESET)')"
+	@grep -E '^(test|test-file|test-no-coverage):.*?## .*$$' $(MAKEFILE_LIST) \
+		| awk 'BEGIN {FS = ":.*?## "}; {printf "$(YELLOW)%-25s$(RESET) %s\n", $$1, $$2}'
+	@echo ""
+	@echo "$$(printf '$(GREEN)')Quality$$(printf '$(RESET)')"
+	@grep -E '^(review):.*?## .*$$' $(MAKEFILE_LIST) \
+		| awk 'BEGIN {FS = ":.*?## "}; {printf "$(YELLOW)%-25s$(RESET) %s\n", $$1, $$2}'
+	@echo ""
+	@echo "$$(printf '$(GREEN)')Reports$$(printf '$(RESET)')"
+	@grep -E '^(show-reports):.*?## .*$$' $(MAKEFILE_LIST) \
+		| awk 'BEGIN {FS = ":.*?## "}; {printf "$(YELLOW)%-25s$(RESET) %s\n", $$1, $$2}'
+	@echo ""
+	@echo "$$(printf '$(GREEN)')Cleanup$$(printf '$(RESET)')"
+	@grep -E '^(clean):.*?## .*$$' $(MAKEFILE_LIST) \
+		| awk 'BEGIN {FS = ":.*?## "}; {printf "$(YELLOW)%-25s$(RESET) %s\n", $$1, $$2}'
diff --git a/composer.json b/composer.json
index da65250..0af7298 100644
--- a/composer.json
+++ b/composer.json
@@ -43,30 +43,27 @@
         }
     },
     "require": {
-        "php": "^8.3",
+        "php": "^8.5",
         "ext-bcmath": "*"
     },
     "require-dev": {
-        "phpmd/phpmd": "^2.15",
-        "phpunit/phpunit": "^11",
-        "phpstan/phpstan": "^1",
-        "infection/infection": "^0",
-        "squizlabs/php_codesniffer": "^3.11"
+        "phpunit/phpunit": "^11.5",
+        "phpstan/phpstan": "^2.1",
+        "infection/infection": "^0.32",
+        "squizlabs/php_codesniffer": "^4.0"
     },
     "suggest": {
         "ext-bcmath": "Enables the extension which is an interface to the GNU implementation as a Basic Calculator utility library."
     },
     "scripts": {
-        "test": "phpunit --configuration phpunit.xml tests",
-        "phpcs": "phpcs --standard=PSR12 --extensions=php ./src",
-        "phpmd": "phpmd ./src text phpmd.xml --suffixes php --ignore-violations-on-exit",
-        "phpstan": "phpstan analyse -c phpstan.neon.dist --quiet --no-progress",
-        "test-file": "phpunit --configuration phpunit.xml --no-coverage --filter",
-        "mutation-test": "infection --only-covered --threads=max --logger-html=report/coverage/mutation-report.html --coverage=report/coverage",
-        "test-no-coverage": "phpunit --configuration phpunit.xml --no-coverage tests",
+        "test": "php -d memory_limit=2G ./vendor/bin/phpunit --configuration phpunit.xml tests",
+        "phpcs": "php ./vendor/bin/phpcs --standard=PSR12 --extensions=php ./src",
+        "phpstan": "php ./vendor/bin/phpstan analyse -c phpstan.neon.dist --quiet --no-progress",
+        "test-file": "php ./vendor/bin/phpunit --configuration phpunit.xml --no-coverage --filter",
+        "mutation-test": "php ./vendor/bin/infection --threads=max --logger-html=report/coverage/mutation-report.html --coverage=report/coverage",
+        "test-no-coverage": "php ./vendor/bin/phpunit --configuration phpunit.xml --no-coverage tests",
         "review": [
             "@phpcs",
-            "@phpmd",
             "@phpstan"
         ],
         "tests": [
diff --git a/phpstan.neon.dist b/phpstan.neon.dist
index e2ccbfc..3e20b2a 100644
--- a/phpstan.neon.dist
+++ b/phpstan.neon.dist
@@ -6,6 +6,7 @@ parameters:
   ignoreErrors:
     - '#does not accept#'
     - '#Binary operation#'
+    - '#should return numeric-string#'
     - '#Access to an undefined property#'
     - '#function number_format expects int#'
     - '#expects TinyBlocks\\Math\\BigNumber#'
diff --git a/src/BigNumber.php b/src/BigNumber.php
index ad3b972..7e2ed38 100644
--- a/src/BigNumber.php
+++ b/src/BigNumber.php
@@ -139,7 +139,7 @@ public function toFloat(): float;
     /**
      * Converts the current BigNumber to a string representation.
      *
-     * @return string The string representation of the BigNumber.
+     * @return numeric-string The string representation of the BigNumber.
      */
     public function toString(): string;
 
diff --git a/src/Internal/Exceptions/DivisionByZero.php b/src/Internal/Exceptions/DivisionByZero.php
index 0b4d0e9..c5d2ac6 100644
--- a/src/Internal/Exceptions/DivisionByZero.php
+++ b/src/Internal/Exceptions/DivisionByZero.php
@@ -8,10 +8,10 @@
 
 final class DivisionByZero extends RuntimeException
 {
-    public function __construct(string $dividend, string $divisor)
+    public function __construct(private readonly string $dividend, private readonly string $divisor)
     {
         $template = 'Cannot divide <%.2f> by <%.2f>.';
 
-        parent::__construct(message: sprintf($template, $dividend, $divisor));
+        parent::__construct(message: sprintf($template, $this->dividend, $this->divisor));
     }
 }
diff --git a/src/Internal/Exceptions/InvalidNumber.php b/src/Internal/Exceptions/InvalidNumber.php
index 173541a..81a7969 100644
--- a/src/Internal/Exceptions/InvalidNumber.php
+++ b/src/Internal/Exceptions/InvalidNumber.php
@@ -8,10 +8,10 @@
 
 final class InvalidNumber extends RuntimeException
 {
-    public function __construct(string $value)
+    public function __construct(private readonly string $value)
     {
         $template = 'The value <%s> is not a valid number.';
 
-        parent::__construct(message: sprintf($template, $value));
+        parent::__construct(message: sprintf($template, $this->value));
     }
 }
diff --git a/src/Internal/Exceptions/InvalidScale.php b/src/Internal/Exceptions/InvalidScale.php
index 85f3070..f1a3a3d 100644
--- a/src/Internal/Exceptions/InvalidScale.php
+++ b/src/Internal/Exceptions/InvalidScale.php
@@ -8,10 +8,13 @@
 
 final class InvalidScale extends RuntimeException
 {
-    public function __construct(int $value, int $minimum, int $maximum)
-    {
+    public function __construct(
+        private readonly int $value,
+        private readonly int $minimum,
+        private readonly int $maximum
+    ) {
         $template = 'Scale value <%s> is invalid. The value must be between <%s> and <%s>.';
 
-        parent::__construct(message: sprintf($template, $value, $minimum, $maximum));
+        parent::__construct(message: sprintf($template, $this->value, $this->minimum, $this->maximum));
     }
 }
diff --git a/src/Internal/Exceptions/MathOperationsNotAvailable.php b/src/Internal/Exceptions/MathOperationsNotAvailable.php
index 8a47fc9..40257e8 100644
--- a/src/Internal/Exceptions/MathOperationsNotAvailable.php
+++ b/src/Internal/Exceptions/MathOperationsNotAvailable.php
@@ -8,10 +8,10 @@
 
 final class MathOperationsNotAvailable extends RuntimeException
 {
-    public function __construct(array $extensions)
+    public function __construct(private readonly array $extensions)
     {
         $template = 'There are no implementations available. Enable one of these <%s> extensions.';
 
-        parent::__construct(message: sprintf($template, implode(',', $extensions)));
+        parent::__construct(message: sprintf($template, implode(',', $this->extensions)));
     }
 }
diff --git a/src/Internal/Exceptions/NonNegativeValue.php b/src/Internal/Exceptions/NonNegativeValue.php
index 06b1458..3304b39 100644
--- a/src/Internal/Exceptions/NonNegativeValue.php
+++ b/src/Internal/Exceptions/NonNegativeValue.php
@@ -9,10 +9,10 @@
 
 final class NonNegativeValue extends RuntimeException
 {
-    public function __construct(Number $number)
+    public function __construct(private readonly Number $number)
     {
         $template = 'Value <%s> is not valid. Must be a negative number less than zero.';
 
-        parent::__construct(message: sprintf($template, $number->value));
+        parent::__construct(message: sprintf($template, $this->number->value));
     }
 }
diff --git a/src/Internal/Exceptions/NonPositiveValue.php b/src/Internal/Exceptions/NonPositiveValue.php
index f20ffa5..ad3446f 100644
--- a/src/Internal/Exceptions/NonPositiveValue.php
+++ b/src/Internal/Exceptions/NonPositiveValue.php
@@ -9,10 +9,10 @@
 
 final class NonPositiveValue extends RuntimeException
 {
-    public function __construct(Number $number)
+    public function __construct(private readonly Number $number)
     {
         $template = 'Value <%s> is not valid. Must be a positive number greater than zero.';
 
-        parent::__construct(message: sprintf($template, $number->value));
+        parent::__construct(message: sprintf($template, $this->number->value));
     }
 }
diff --git a/src/Internal/Number.php b/src/Internal/Number.php
index 7371d09..758eeeb 100644
--- a/src/Internal/Number.php
+++ b/src/Internal/Number.php
@@ -44,6 +44,10 @@ private function __construct(public readonly string $value)
 
     public static function from(float|string $value): Number
     {
+        if (is_float($value) && is_nan($value)) {
+            throw new InvalidNumber(value: "NAN");
+        }
+
         return new Number(value: (string)$value);
     }
 
diff --git a/src/Internal/Operations/Adapters/BcMathAdapter.php b/src/Internal/Operations/Adapters/BcMathAdapter.php
index 2aac4a7..d8b8186 100644
--- a/src/Internal/Operations/Adapters/BcMathAdapter.php
+++ b/src/Internal/Operations/Adapters/BcMathAdapter.php
@@ -16,7 +16,7 @@
 {
     public function add(BigNumber $augend, BigNumber $addend): Result
     {
-        $scale = (new Addition(augend: $augend, addend: $addend))->applyScale();
+        $scale = new Addition(augend: $augend, addend: $addend)->applyScale();
         $number = Number::from(
             value: bcadd(
                 $augend->toString(),
@@ -30,7 +30,7 @@ public function add(BigNumber $augend, BigNumber $addend): Result
 
     public function subtract(BigNumber $minuend, BigNumber $subtrahend): Result
     {
-        $scale = (new Subtraction(minuend: $minuend, subtrahend: $subtrahend))->applyScale();
+        $scale = new Subtraction(minuend: $minuend, subtrahend: $subtrahend)->applyScale();
         $number = Number::from(
             value: bcsub(
                 $minuend->toString(),
@@ -44,7 +44,7 @@ public function subtract(BigNumber $minuend, BigNumber $subtrahend): Result
 
     public function multiply(BigNumber $multiplicand, BigNumber $multiplier): Result
     {
-        $scale = (new Multiplication(multiplicand: $multiplicand, multiplier: $multiplier))->applyScale();
+        $scale = new Multiplication(multiplicand: $multiplicand, multiplier: $multiplier)->applyScale();
         $number = Number::from(
             value: bcmul(
                 $multiplicand->toString(),
@@ -58,7 +58,7 @@ public function multiply(BigNumber $multiplicand, BigNumber $multiplier): Result
 
     public function divide(BigNumber $dividend, BigNumber $divisor): Result
     {
-        $scale = (new Division(dividend: $dividend, divisor: $divisor))->applyScale();
+        $scale = new Division(dividend: $dividend, divisor: $divisor)->applyScale();
         $number = Number::from(
             value: bcdiv(
                 $dividend->toString(),
diff --git a/src/Internal/Operations/Adapters/Scales/Addition.php b/src/Internal/Operations/Adapters/Scales/Addition.php
index 57da81b..6a026de 100644
--- a/src/Internal/Operations/Adapters/Scales/Addition.php
+++ b/src/Internal/Operations/Adapters/Scales/Addition.php
@@ -25,10 +25,6 @@ public function applyScale(): Scale
             $augendScale = $this->augendScale->scaleOf(value: $this->augend->toString());
             $addendScale = $this->addendScale->scaleOf(value: $this->addend->toString());
 
-            if ($augendScale->equals(other: $addendScale)) {
-                return $augendScale;
-            }
-
             return $augendScale->greaterScale(other: $addendScale);
         }
 
diff --git a/src/Internal/Operations/Adapters/Scales/Subtraction.php b/src/Internal/Operations/Adapters/Scales/Subtraction.php
index 618a1c7..27d093a 100644
--- a/src/Internal/Operations/Adapters/Scales/Subtraction.php
+++ b/src/Internal/Operations/Adapters/Scales/Subtraction.php
@@ -23,11 +23,7 @@ public function applyScale(): Scale
     {
         if ($this->minuendScale->hasAutomaticScale() && $this->subtrahendScale->hasAutomaticScale()) {
             $minuendScale = $this->minuendScale->scaleOf(value: $this->minuend->toString());
-            $subtrahendScale = $this->minuendScale->scaleOf(value: $this->subtrahend->toString());
-
-            if ($minuendScale->equals(other: $subtrahendScale)) {
-                return $minuendScale;
-            }
+            $subtrahendScale = $this->subtrahendScale->scaleOf(value: $this->subtrahend->toString());
 
             return $minuendScale->greaterScale(other: $subtrahendScale);
         }
diff --git a/tests/Internal/NumberTest.php b/tests/Internal/NumberTest.php
index cb271f5..da0d3b3 100644
--- a/tests/Internal/NumberTest.php
+++ b/tests/Internal/NumberTest.php
@@ -24,6 +24,20 @@ public function testInvalidNumber(mixed $value): void
         Number::from(value: $value);
     }
 
+    public function testInvalidNumberWhenValueIsNaN(): void
+    {
+        /** @Given a Not a Number (NaN) value */
+        $value = NAN;
+        $template = 'The value <NAN> is not a valid number.';
+
+        /** @Then an InvalidNumber exception should be thrown */
+        $this->expectException(InvalidNumber::class);
+        $this->expectExceptionMessage($template);
+
+        /** @When attempting to create a Number instance with the NaN value */
+        Number::from(value: $value);
+    }
+
     public static function invalidNumberDataProvider(): array
     {
         return [
@@ -32,7 +46,6 @@ public static function invalidNumberDataProvider(): array
             'String "null"'           => ['value' => 'null'],
             'String "true"'           => ['value' => 'true'],
             'String "false"'          => ['value' => 'false'],
-            'Not a Number (NaN)'      => ['value' => NAN],
             'Positive infinity'       => ['value' => INF],
             'Negative infinity'       => ['value' => -INF],
             'Zero followed by x'      => ['value' => '0x'],
diff --git a/tests/Internal/Operations/MathOperationsFactoryTest.php b/tests/Internal/Operations/MathOperationsFactoryTest.php
index 416e877..f375a8f 100644
--- a/tests/Internal/Operations/MathOperationsFactoryTest.php
+++ b/tests/Internal/Operations/MathOperationsFactoryTest.php
@@ -17,6 +17,6 @@ public function testMathOperationsNotAvailable(): void
         $this->expectException(MathOperationsNotAvailable::class);
         $this->expectExceptionMessage(sprintf($template, 'bcmath'));
 
-        (new MathOperationsFactory(extension: new ExtensionAdapterMock()))->build();
+        new MathOperationsFactory(extension: new ExtensionAdapterMock())->build();
     }
 }