diff --git a/src/Hydrator/Strategy/ParagraphsStrategy.php b/src/Hydrator/Strategy/ParagraphsStrategy.php
index 7a08f77..9636b6d 100644
--- a/src/Hydrator/Strategy/ParagraphsStrategy.php
+++ b/src/Hydrator/Strategy/ParagraphsStrategy.php
@@ -36,10 +36,23 @@ public function __construct()
     public function extract($value)
     {
         return array_map(function(Paragraph $paragraphEntity) {
+            $textProperty = $paragraphEntity->getProperty()
+                ? $this->textPropertyStrategy->extract($paragraphEntity->getProperty())
+                : null;
+
+            $boundingBox = $paragraphEntity->getBoundingBox()
+                ? $this->boundingPolyStrategy->extract($paragraphEntity->getBoundingBox())
+                : null;
+
+            $words = $paragraphEntity->getWords()
+                ? $this->wordsStrategy->extract($paragraphEntity->getWords())
+                : null;
+
+
             return array_filter([
-                'property' => $this->textPropertyStrategy->extract($paragraphEntity->getProperty()),
-                'boundingBox' => $this->boundingPolyStrategy->extract($paragraphEntity->getBoundingBox()),
-                'words' => $this->wordsStrategy->extract($paragraphEntity->getWords()),
+                'property' => $textProperty,
+                'boundingBox' => $boundingBox,
+                'words' => $words,
             ]);
         }, $value);
     }
@@ -51,13 +64,20 @@ public function extract($value)
     public function hydrate($value)
     {
         $paragraphEntities = [];
-
         foreach ($value as $paragraphEntityInfo) {
-            $paragraphEntities[] = new Paragraph(
-                $this->textPropertyStrategy->hydrate($paragraphEntityInfo['property']),
-                $this->boundingPolyStrategy->hydrate($paragraphEntityInfo['boundingBox']),
-                $this->wordsStrategy->hydrate($paragraphEntityInfo['words'])
-            );
+            $textProperty = isset($paragraphEntityInfo['property'])
+                ? $this->textPropertyStrategy->hydrate($paragraphEntityInfo['property'])
+                : null;
+
+            $boundingBox = isset($paragraphEntityInfo['boundingBox'])
+                ? $this->boundingPolyStrategy->hydrate($paragraphEntityInfo['boundingBox'])
+                : null;
+
+            $words = isset($paragraphEntityInfo['words'])
+                ? $this->wordsStrategy->hydrate($paragraphEntityInfo['words'])
+                : null;
+
+            $paragraphEntities[] = new Paragraph($textProperty, $boundingBox, $words);
         }
 
         return $paragraphEntities;
diff --git a/src/Hydrator/Strategy/SymbolsStrategy.php b/src/Hydrator/Strategy/SymbolsStrategy.php
index 017520c..f3b605f 100644
--- a/src/Hydrator/Strategy/SymbolsStrategy.php
+++ b/src/Hydrator/Strategy/SymbolsStrategy.php
@@ -2,9 +2,7 @@
 
 namespace Vision\Hydrator\Strategy;
 
-use Vision\Annotation\Paragraph;
 use Vision\Annotation\Symbol;
-use Vision\Annotation\Word;
 use Zend\Hydrator\Strategy\StrategyInterface;
 
 class SymbolsStrategy implements StrategyInterface
@@ -32,9 +30,17 @@ public function __construct()
     public function extract($value)
     {
         return array_map(function(Symbol $symbolEntity) {
+            $textProperty = $symbolEntity->getProperty()
+                ? $this->textPropertyStrategy->extract($symbolEntity->getProperty())
+                : null;
+
+            $boundingBox = $symbolEntity->getBoundingBox()
+                ? $this->boundingPolyStrategy->extract($symbolEntity->getBoundingBox())
+                : null;
+
             return array_filter([
-                'property' => $this->textPropertyStrategy->extract($symbolEntity->getProperty()),
-                'boundingBox' => $this->boundingPolyStrategy->extract($symbolEntity->getBoundingBox()),
+                'property' => $textProperty,
+                'boundingBox' => $boundingBox,
                 'text' => $symbolEntity->getText(),
             ]);
         }, $value);
@@ -49,10 +55,18 @@ public function hydrate($value)
         $symbolEntities = [];
 
         foreach ($value as $symbolEntityInfo) {
+            $textProperty = isset($symbolEntityInfo['property'])
+                ? $this->textPropertyStrategy->hydrate($symbolEntityInfo['property'])
+                : null;
+
+            $boundingBox = isset($symbolEntityInfo['boundingBox'])
+                ? $this->boundingPolyStrategy->hydrate($symbolEntityInfo['boundingBox'])
+                : null;
+
             $symbolEntities[] = new Symbol(
-                $this->textPropertyStrategy->hydrate($symbolEntityInfo['property']),
-                $this->boundingPolyStrategy->hydrate($symbolEntityInfo['boundingBox']),
-                $symbolEntityInfo['text']
+                $textProperty,
+                $boundingBox,
+                isset($symbolEntityInfo['text']) ? $symbolEntityInfo['text'] : null
             );
         }