diff --git a/.php-cs-fixer.php b/.php-cs-fixer.php
index 29ef69ef..33f4467d 100644
--- a/.php-cs-fixer.php
+++ b/.php-cs-fixer.php
@@ -15,9 +15,14 @@
     '@Symfony' => true,
     '@Symfony:risky' => true,
     'array_syntax' => ['syntax' => 'short'],
-    'braces' => [
-        'allow_single_line_closure' => true,
-    ],
+    'single_space_around_construct' => true,
+    'control_structure_braces' => true,
+    'control_structure_continuation_position' => true,
+    'declare_parentheses' => true,
+    'no_multiple_statements_per_line' => true,
+    'braces_position' => true,
+    'statement_indentation' => true,
+    'no_extra_blank_lines' => true,
     'concat_space' => [
         'spacing' => 'one',
     ],
diff --git a/src/CompiledContainer.php b/src/CompiledContainer.php
index 3120600a..74e23a23 100644
--- a/src/CompiledContainer.php
+++ b/src/CompiledContainer.php
@@ -16,6 +16,7 @@
 use Invoker\ParameterResolver\DefaultValueResolver;
 use Invoker\ParameterResolver\NumericArrayResolver;
 use Invoker\ParameterResolver\ResolverChain;
+use Psr\Container\NotFoundExceptionInterface;
 
 /**
  * Compiled version of the dependency injection container.
@@ -112,4 +113,21 @@ protected function resolveFactory($callable, $entryName, array $extraParameters
             throw new InvalidDefinition("Entry \"$entryName\" cannot be resolved: " . $e->getMessage());
         }
     }
+
+    /**
+     * Resolve a placeholder in string definition
+     * - wrap possible NotFound exception to conform to the one from StringDefinition::resolveExpression.
+     */
+    protected function resolveStringPlaceholder(string $placeholder, string $entryName) : mixed
+    {
+        try {
+            return $this->delegateContainer->get($placeholder);
+        } catch (NotFoundExceptionInterface $e) {
+            throw new DependencyException(sprintf(
+                "Error while parsing string expression for entry '%s': %s",
+                $entryName,
+                $e->getMessage()
+            ), 0, $e);
+        }
+    }
 }
diff --git a/src/Compiler/Compiler.php b/src/Compiler/Compiler.php
index eeea2403..ff25b3aa 100644
--- a/src/Compiler/Compiler.php
+++ b/src/Compiler/Compiler.php
@@ -214,9 +214,10 @@ private function compileDefinition(string $entryName, Definition $definition) :
                 }
                 break;
             case $definition instanceof StringDefinition:
-                $entryName = $this->compileValue($definition->getName());
-                $expression = $this->compileValue($definition->getExpression());
-                $code = 'return \DI\Definition\StringDefinition::resolveExpression(' . $entryName . ', ' . $expression . ', $this->delegateContainer);';
+                $expression = $definition->getExpression();
+                $callback = fn (array $matches) : string => '\'.$this->resolveStringPlaceholder(' . $this->compileValue($matches[1]) . ', ' . $this->compileValue($definition->getName()) . ').\'';
+                $value = preg_replace_callback('#\{([^\{\}]+)\}#', $callback, $expression);
+                $code = 'return \'' . $value . '\';';
                 break;
             case $definition instanceof EnvironmentVariableDefinition:
                 $variableName = $this->compileValue($definition->getVariableName());