diff --git a/src/Types/GeometryCollectionType.php b/src/Types/GeometryCollectionType.php
index a2cde58..8aedd4f 100644
--- a/src/Types/GeometryCollectionType.php
+++ b/src/Types/GeometryCollectionType.php
@@ -11,7 +11,7 @@
  */
 class GeometryCollectionType extends GeometryType
 {
-    public function getName()
+    public function getName() : string
     {
         return 'GeometryCollection';
     }
diff --git a/src/Types/GeometryType.php b/src/Types/GeometryType.php
index 31e82bf..56e70e9 100644
--- a/src/Types/GeometryType.php
+++ b/src/Types/GeometryType.php
@@ -50,12 +50,12 @@ protected function hasKnownSubclasses() : bool
         return true;
     }
 
-    public function getName()
+    public function getName() : string
     {
         return 'Geometry';
     }
 
-    public function getSQLDeclaration(array $column, AbstractPlatform $platform)
+    public function getSQLDeclaration(array $column, AbstractPlatform $platform) : string
     {
         if ($platform->getName() === 'postgresql') {
             return 'GEOMETRY';
@@ -64,7 +64,7 @@ public function getSQLDeclaration(array $column, AbstractPlatform $platform)
         return strtoupper($this->getName());
     }
 
-    public function convertToPHPValue($value, AbstractPlatform $platform)
+    public function convertToPHPValue($value, AbstractPlatform $platform) : ?Geometry
     {
         /** @var string|resource|null $value */
         if ($value === null) {
@@ -89,7 +89,7 @@ public function convertToPHPValue($value, AbstractPlatform $platform)
         return new $proxyClassName($value, true, self::$srid);
     }
 
-    public function convertToDatabaseValue($value, AbstractPlatform $platform)
+    public function convertToDatabaseValue($value, AbstractPlatform $platform) : ?string
     {
         if ($value === null) {
             return null;
@@ -104,7 +104,7 @@ public function convertToDatabaseValue($value, AbstractPlatform $platform)
         throw new \UnexpectedValueException(sprintf('Expected %s, got %s.', Geometry::class, $type));
     }
 
-    public function convertToDatabaseValueSQL($sqlExpr, AbstractPlatform $platform)
+    public function convertToDatabaseValueSQL($sqlExpr, AbstractPlatform $platform) : string
     {
         if ($platform->getName() === 'mysql') {
             $sqlExpr = sprintf('BINARY %s', $sqlExpr);
@@ -113,22 +113,22 @@ public function convertToDatabaseValueSQL($sqlExpr, AbstractPlatform $platform)
         return sprintf('ST_GeomFromWKB(%s, %d)', $sqlExpr, self::$srid);
     }
 
-    public function convertToPHPValueSQL($sqlExpr, $platform)
+    public function convertToPHPValueSQL($sqlExpr, $platform) : string
     {
         return sprintf('ST_AsBinary(%s)', $sqlExpr);
     }
 
-    public function canRequireSQLConversion()
+    public function canRequireSQLConversion() : bool
     {
         return true;
     }
 
-    public function requiresSQLCommentHint(AbstractPlatform $platform)
+    public function requiresSQLCommentHint(AbstractPlatform $platform) : bool
     {
         return true;
     }
 
-    public function getBindingType()
+    public function getBindingType() : int
     {
         return \PDO::PARAM_LOB;
     }
diff --git a/src/Types/LineStringType.php b/src/Types/LineStringType.php
index 483769e..0b2fe6b 100644
--- a/src/Types/LineStringType.php
+++ b/src/Types/LineStringType.php
@@ -11,7 +11,7 @@
  */
 class LineStringType extends GeometryType
 {
-    public function getName()
+    public function getName() : string
     {
         return 'LineString';
     }
diff --git a/src/Types/MultiLineStringType.php b/src/Types/MultiLineStringType.php
index 832057c..657568c 100644
--- a/src/Types/MultiLineStringType.php
+++ b/src/Types/MultiLineStringType.php
@@ -11,7 +11,7 @@
  */
 class MultiLineStringType extends GeometryType
 {
-    public function getName()
+    public function getName() : string
     {
         return 'MultiLineString';
     }
diff --git a/src/Types/MultiPointType.php b/src/Types/MultiPointType.php
index 2ec14f4..618147e 100644
--- a/src/Types/MultiPointType.php
+++ b/src/Types/MultiPointType.php
@@ -11,7 +11,7 @@
  */
 class MultiPointType extends GeometryType
 {
-    public function getName()
+    public function getName() : string
     {
         return 'MultiPoint';
     }
diff --git a/src/Types/MultiPolygonType.php b/src/Types/MultiPolygonType.php
index 1bacc01..005df00 100644
--- a/src/Types/MultiPolygonType.php
+++ b/src/Types/MultiPolygonType.php
@@ -11,7 +11,7 @@
  */
 class MultiPolygonType extends GeometryType
 {
-    public function getName()
+    public function getName() : string
     {
         return 'MultiPolygon';
     }
diff --git a/src/Types/PointType.php b/src/Types/PointType.php
index eeec1a1..5f371d5 100644
--- a/src/Types/PointType.php
+++ b/src/Types/PointType.php
@@ -11,7 +11,7 @@
  */
 class PointType extends GeometryType
 {
-    public function getName()
+    public function getName() : string
     {
         return 'Point';
     }
diff --git a/src/Types/PolygonType.php b/src/Types/PolygonType.php
index 6b8c306..eab6a35 100644
--- a/src/Types/PolygonType.php
+++ b/src/Types/PolygonType.php
@@ -11,7 +11,7 @@
  */
 class PolygonType extends GeometryType
 {
-    public function getName()
+    public function getName() : string
     {
         return 'Polygon';
     }