diff --git a/Model/Processor/ImportProcessor.php b/Model/Processor/ImportProcessor.php
index 470b643..56ac276 100644
--- a/Model/Processor/ImportProcessor.php
+++ b/Model/Processor/ImportProcessor.php
@@ -19,6 +19,8 @@
 class ImportProcessor extends AbstractProcessor implements ImportProcessorInterface
 {
     private const DELETE_CONFIG_FLAG = '!!DELETE';
+    private const KEEP_CONFIG_FLAG = '!!KEEP';
+
     /**
      * @var WriterInterface
      */
@@ -85,46 +87,87 @@ public function __construct(
     public function process()
     {
         $files = $this->finder->find();
-        if (0 === count($files) && false === $this->getInput()->getOption('allow-empty-directories')) {
-            throw new \InvalidArgumentException('No files found for format: *.' . $this->getFormat());
-        } else {
-            $this->getOutput()->writeln('No files found for format: *.' . $this->getFormat());
-            $this->getOutput()->writeln('Maybe this is expected behaviour, because you passed the --allow-empty-directories option.');
+
+        if (0 === count($files)) {
+            if (false === $this->getInput()->getOption('allow-empty-directories')) {
+                throw new \InvalidArgumentException('No files found for format: *.' . $this->getFormat());
+            } else {
+                $this->getOutput()->writeln('No files found for format: *.' . $this->getFormat());
+                $this->getOutput()->writeln('Maybe this is expected behaviour, because you passed the --allow-empty-directories option.');
+                $this->getOutput()->writeln(' ');
+            }
         }
 
-        foreach ($files as $file) {
-            $valuesSet = 0;
-            $configurations = $this->getConfigurationsFromFile($file);
-            foreach ($configurations as $configPath => $configValues) {
-                $scopeConfigValues = $this->transformConfigToScopeConfig($configPath, $configValues);
-                foreach ($scopeConfigValues as $scopeConfigValue) {
-                    if ($scopeConfigValue['value'] === self::DELETE_CONFIG_FLAG) {
-                        $this->configWriter->delete(
-                            $configPath,
-                            $scopeConfigValue['scope'],
-                            $this->scopeConverter->convert($scopeConfigValue['scope_id'], $scopeConfigValue['scope'])
-                        );
+        $configurationValues = $this->collectConfigurationValues($files);
+        if (0 === count($configurationValues)) {
+            return;
+        }
 
-                        $this->getOutput()->writeln(sprintf('<comment>%s => %s</comment>', $configPath, 'DELETED'));
-                        $valuesSet++;
+        foreach ($configurationValues as $configPath => $configValue) {
+            foreach ($configValue as $scopeType => $scopeValue) {
+                foreach ($scopeValue as $scopeId => $value) {
+                    if ($value === self::DELETE_CONFIG_FLAG) {
+                        $this->configWriter->delete($configPath, $scopeType, $scopeId);
+                        $this->getOutput()->writeln(sprintf('<comment>[%s] [%s] %s => %s</comment>', $scopeType, $scopeId, $configPath, 'DELETED'));
 
                         continue;
                     }
 
-                    $this->configWriter->save(
-                        $configPath,
-                        $scopeConfigValue['value'],
-                        $scopeConfigValue['scope'],
-                        $this->scopeConverter->convert($scopeConfigValue['scope_id'], $scopeConfigValue['scope'])
-                    );
+                    if ($value === self::KEEP_CONFIG_FLAG) {
+                        $this->getOutput()->writeln(sprintf('<comment>[%s] [%s] %s => %s</comment>', $scopeType, $scopeId, $configPath, 'KEPT'));
+
+                        continue;
+                    }
+
+                    $this->configWriter->save($configPath, $value, $scopeType, $scopeId);
+                    $this->getOutput()->writeln(sprintf('<comment>[%s] [%s] %s => %s</comment>', $scopeType, $scopeId, $configPath, $value));
+                }
+            }
+        }
+    }
+
+    /**
+     * @param array $files
+     *
+     * @return array
+     */
+    private function collectConfigurationValues(array $files): array
+    {
+        $buffer = [];
 
-                    $this->getOutput()->writeln(sprintf('<comment>%s => %s</comment>', $configPath, $scopeConfigValue['value']));
+        foreach ($files as $file) {
+            $valuesSet = 0;
+
+            $configurations = $this->getConfigurationsFromFile($file);
+            foreach ($configurations as $configPath => $configValues) {
+                if (!isset($buffer[$configPath])) {
+                    $buffer[$configPath] = [];
+                }
+
+                $scopeConfigValues = $this->transformConfigToScopeConfig($configPath, $configValues);
+                foreach ($scopeConfigValues as $scopeConfigValue) {
+                    $scopeType = $scopeConfigValue['scope'];
+                    $scopeId = $this->scopeConverter->convert($scopeConfigValue['scope_id'], $scopeConfigValue['scope']);
+                    $buffer[$configPath][$scopeType][$scopeId] = $scopeConfigValue['value'];
                     $valuesSet++;
                 }
             }
 
-            $this->getOutput()->writeln(sprintf('<info>Processed: %s with %s value(s).</info>', $file, $valuesSet));
+            if (0 === $valuesSet) {
+                continue;
+            }
+
+            $this->getOutput()->writeln(sprintf(
+                '<info>Collected configuration values from %s with %s %s.</info>',
+                $file,
+                $valuesSet,
+                $valuesSet === 1 ? 'value' : 'values'
+            ));
         }
+
+        $this->getOutput()->writeln(' '); // Add empty line to make output in terminal nicer.
+
+        return $buffer;
     }
 
     /**
diff --git a/Test/Unit/Model/Processor/ImportProcessorTest.php b/Test/Unit/Model/Processor/ImportProcessorTest.php
index e1be178..c54362a 100644
--- a/Test/Unit/Model/Processor/ImportProcessorTest.php
+++ b/Test/Unit/Model/Processor/ImportProcessorTest.php
@@ -14,6 +14,7 @@
 use Semaio\ConfigImportExport\Model\File\Reader\YamlReader;
 use Semaio\ConfigImportExport\Model\Processor\ImportProcessor;
 use Semaio\ConfigImportExport\Model\Validator\ScopeValidatorInterface;
+use Symfony\Component\Console\Input\InputInterface;
 use Symfony\Component\Console\Output\OutputInterface;
 
 class ImportProcessorTest extends TestCase
@@ -67,6 +68,9 @@ public function processWithoutFiles(): void
         $this->expectException(InvalidArgumentException::class);
 
         $processor = new ImportProcessor($this->configWriterMock, $this->scopeValidatorMock, $this->scopeConverterMock, []);
+        $inputMock = $this->getMockBuilder(InputInterface::class)->getMock();
+        $inputMock->method('getOption')->with('allow-empty-directories')->willReturn(false);
+        $processor->setInput($inputMock);
         $processor->setFinder($finderMock);
         $processor->process();
     }
@@ -126,6 +130,16 @@ public function process(): void
                     0 => '!!DELETE',
                 ],
             ],
+            'test/config/custom_field_to_be_keeped' => [
+                'default' => [
+                    0 => 'VALUE_THAT_SHOULD_NOT_BE_PROCESSED',
+                ],
+            ],
+            'test/config/custom_field_to_be_keeped' => [
+                'default' => [
+                    0 => '!!KEEP',
+                ],
+            ],
         ];
 
         $readerMock = $this->getMockBuilder(YamlReader::class)
@@ -133,7 +147,7 @@ public function process(): void
             ->getMock();
         $readerMock->expects($this->once())->method('parse')->willReturn($parseResult);
 
-        $this->scopeValidatorMock->expects($this->exactly(2))->method('validate')->willReturn(true);
+        $this->scopeValidatorMock->expects($this->exactly(3))->method('validate')->willReturn(true);
         $this->configWriterMock->expects($this->once())->method('save');
         $this->configWriterMock->expects($this->once())->method('delete');
 
diff --git a/docs/config-import.md b/docs/config-import.md
index 05bfd53..a54645f 100644
--- a/docs/config-import.md
+++ b/docs/config-import.md
@@ -97,6 +97,18 @@ vendorx/general/api_key:
     0: "!!DELETE"
 ```
 
+### Keep Config
+
+To ensure that a specific configuration value will not be changed by the config importer, please use the following string as configuration value:
+
+```yaml
+vendorx/general/api_key:
+  default:
+    0: "!!KEEP"
+```
+
+This is helpful when you've got the same settings across different environments but want to keep one environment ( `X` env) unchanged without showing the exact value in the config file. It's a common scenario, especially when dealing with sensitive data. You really should only keep that kind of info in the environment’s database, not in your GIT repo.
+
 ### Recursive folder setup
 
 If you choose to store your configuration files in subdirectories, e.g. per vendor, the recommended folder setup should look like this: