diff --git a/peck.json b/peck.json
index eaa17abf..41ecc4e9 100644
--- a/peck.json
+++ b/peck.json
@@ -2,7 +2,9 @@
     "preset": "base",
     "ignore": {
         "words": [
-            "php"
+            "php",
+            "strtolower",
+            "fg"
         ],
         "paths": [
             "tests"
diff --git a/src/Checkers/SourceCodeChecker.php b/src/Checkers/SourceCodeChecker.php
index 7dc7ac39..dfc6eb81 100644
--- a/src/Checkers/SourceCodeChecker.php
+++ b/src/Checkers/SourceCodeChecker.php
@@ -19,6 +19,7 @@
 use ReflectionProperty;
 use Symfony\Component\Finder\Finder;
 use Symfony\Component\Finder\SplFileInfo;
+use Throwable;
 
 /**
  * @internal
@@ -92,6 +93,7 @@ private function getIssuesFromSourceFile(SplFileInfo $file): array
             ...$this->getMethodNames($reflection),
             ...$this->getPropertyNames($reflection),
             ...$this->getConstantNames($reflection),
+            ...$this->getStringValues($file),
         ];
 
         if ($docComment = $reflection->getDocComment()) {
@@ -125,6 +127,36 @@ private function getIssuesFromSourceFile(SplFileInfo $file): array
         return $issues;
     }
 
+    /**
+     * Get the string values contained in the given file.
+     *
+     * @return array<int, string>
+     */
+    private function getStringValues(SplFileInfo $file): array
+    {
+        try {
+            $tokens = token_get_all($file->getContents());
+        } catch (Throwable) {
+            return [];
+        }
+
+        foreach ($tokens as $token) {
+            if (is_array($token) && $token[0] === T_CONSTANT_ENCAPSED_STRING) {
+                // Remove the surrounding quotes from the string
+                $string = substr($token[1], 1, -1);
+
+                // Handle escaped quotes depending on string type
+                if ($token[1][0] === '"') {
+                    $string = stripcslashes($string);
+                }
+
+                $stringsToCheck[] = $string;
+            }
+        }
+
+        return $stringsToCheck ?? [];
+    }
+
     /**
      * Get the method names contained in the given reflection.
      *
diff --git a/stubs/presets/base.stub b/stubs/presets/base.stub
index 0a04423c..61ba69e9 100644
--- a/stubs/presets/base.stub
+++ b/stubs/presets/base.stub
@@ -119,6 +119,7 @@ sqs
 src
 ssl
 sso
+str
 stringable
 symfony
 throwable
@@ -139,6 +140,7 @@ unformatted
 unsuspend
 upsert
 uri
+utf
 uuid
 validator
 verifier