diff --git a/Definition/ArrayNode.php b/Definition/ArrayNode.php
index 59b6f1159..4e9deacaa 100644
--- a/Definition/ArrayNode.php
+++ b/Definition/ArrayNode.php
@@ -207,7 +207,7 @@ public function addChild(NodeInterface $node)
     protected function finalizeValue($value)
     {
         if (false === $value) {
-            throw new UnsetKeyException(sprintf('Unsetting key for path "%s", value: %s.', $this->getPath(), json_encode($value)));
+            throw new UnsetKeyException(sprintf('Unsetting key for path "%s", value: "%s".', $this->getPath(), json_encode($value)));
         }
 
         foreach ($this->children as $name => $child) {
diff --git a/Definition/PrototypedArrayNode.php b/Definition/PrototypedArrayNode.php
index 8e18d077d..cad428f72 100644
--- a/Definition/PrototypedArrayNode.php
+++ b/Definition/PrototypedArrayNode.php
@@ -175,7 +175,7 @@ public function addChild(NodeInterface $node)
     protected function finalizeValue($value)
     {
         if (false === $value) {
-            throw new UnsetKeyException(sprintf('Unsetting key for path "%s", value: %s.', $this->getPath(), json_encode($value)));
+            throw new UnsetKeyException(sprintf('Unsetting key for path "%s", value: "%s".', $this->getPath(), json_encode($value)));
         }
 
         foreach ($value as $k => $v) {
diff --git a/FileLocator.php b/FileLocator.php
index 965f940d4..2e82bf0be 100644
--- a/FileLocator.php
+++ b/FileLocator.php
@@ -68,7 +68,7 @@ public function locate(string $name, string $currentPath = null, bool $first = t
         }
 
         if (!$filepaths) {
-            throw new FileLocatorFileNotFoundException(sprintf('The file "%s" does not exist (in: %s).', $name, implode(', ', $paths)), 0, null, $notfound);
+            throw new FileLocatorFileNotFoundException(sprintf('The file "%s" does not exist (in: "%s").', $name, implode('", "', $paths)), 0, null, $notfound);
         }
 
         return $filepaths;