diff --git a/controllers/class.EditDocument.php b/controllers/class.EditDocument.php
index ca4b38218..483972780 100644
--- a/controllers/class.EditDocument.php
+++ b/controllers/class.EditDocument.php
@@ -52,7 +52,7 @@ class SeedDMS_Controller_EditDocument extends SeedDMS_Controller_Common {
 			$expires = $this->params['expires'];
 			$oldexpires = $document->getExpires();
 			if ($expires != $oldexpires) {
-				if(!$this->callHook('preSetExpires', $document, $expires)) {
+				if(false === $this->callHook('preSetExpires', $document, $expires)) {
 				}
 
 				if(!$document->setExpires($expires)) {
@@ -61,21 +61,21 @@ class SeedDMS_Controller_EditDocument extends SeedDMS_Controller_Common {
 
 				$document->verifyLastestContentExpriry();
 
-				if(!$this->callHook('postSetExpires', $document, $expires)) {
+				if(false === $this->callHook('postSetExpires', $document, $expires)) {
 				}
 			}
 
 			$keywords = $this->params['keywords'];
 			$oldkeywords = $document->getKeywords();
 			if ($oldkeywords != $keywords) {
-				if(!$this->callHook('preSetKeywords', $document, $keywords, $oldkeywords)) {
+				if(false === $this->callHook('preSetKeywords', $document, $keywords, $oldkeywords)) {
 				}
 
 				if(!$document->setKeywords($keywords)) {
 					return false;
 				}
 
-				if(!$this->callHook('postSetKeywords', $document, $keywords, $oldkeywords)) {
+				if(false === $this->callHook('postSetKeywords', $document, $keywords, $oldkeywords)) {
 				}
 			}
 
@@ -95,21 +95,21 @@ class SeedDMS_Controller_EditDocument extends SeedDMS_Controller_Common {
 
 				if (count($categoriesarr) != count($oldcategories) ||
 						array_diff($categories, $oldcatsids)) {
-					if(!$this->callHook('preSetCategories', $document, $categoriesarr, $oldcategories)) {
+					if(false === $this->callHook('preSetCategories', $document, $categoriesarr, $oldcategories)) {
 					}
 					if(!$document->setCategories($categoriesarr)) {
 						return false;
 					}
-					if(!$this->callHook('postSetCategories', $document, $categoriesarr, $oldcategories)) {
+					if(false === $this->callHook('postSetCategories', $document, $categoriesarr, $oldcategories)) {
 					}
 				}
 			} elseif($oldcategories) {
-				if(!$this->callHook('preSetCategories', $document, array(), $oldcategories)) {
+				if(false === $this->callHook('preSetCategories', $document, array(), $oldcategories)) {
 				}
 				if(!$document->setCategories(array())) {
 					return false;
 				}
-				if(!$this->callHook('postSetCategories', $document, array(), $oldcategories)) {
+				if(false === $this->callHook('postSetCategories', $document, array(), $oldcategories)) {
 				}
 			}
 
@@ -180,7 +180,7 @@ class SeedDMS_Controller_EditDocument extends SeedDMS_Controller_Common {
 			return false;
 		}
 
-		if(!$this->callHook('postEditDocument')) {
+		if(false === $this->callHook('postEditDocument')) {
 		}
 
 		return true;
diff --git a/controllers/class.EditFolder.php b/controllers/class.EditFolder.php
index 7e37d5016..b3a3c572b 100644
--- a/controllers/class.EditFolder.php
+++ b/controllers/class.EditFolder.php
@@ -108,7 +108,7 @@ class SeedDMS_Controller_EditFolder extends SeedDMS_Controller_Common {
 			return false;
 		}
 
-		if(!$this->callHook('postEditFolder')) {
+		if(false === $this->callHook('postEditFolder')) {
 		}
 
 		return true;
diff --git a/controllers/class.EmptyFolder.php b/controllers/class.EmptyFolder.php
index 529fa9a74..a6629923c 100644
--- a/controllers/class.EmptyFolder.php
+++ b/controllers/class.EmptyFolder.php
@@ -68,7 +68,7 @@ class SeedDMS_Controller_EmptyFolder extends SeedDMS_Controller_Common {
 			return false;
 		}
 
-		if(!$this->callHook('postEmptyFolder')) {
+		if(false === $this->callHook('postEmptyFolder')) {
 		}
 
 		return true;
diff --git a/controllers/class.RemoveDocument.php b/controllers/class.RemoveDocument.php
index 70cff8fe1..56e165e6a 100644
--- a/controllers/class.RemoveDocument.php
+++ b/controllers/class.RemoveDocument.php
@@ -68,7 +68,7 @@ class SeedDMS_Controller_RemoveDocument extends SeedDMS_Controller_Common {
 			}
 		}
 
-		if(!$this->callHook('postRemoveDocument')) {
+		if(false === $this->callHook('postRemoveDocument')) {
 		}
 
 		return true;
diff --git a/controllers/class.RemoveFolder.php b/controllers/class.RemoveFolder.php
index 6706eb8e4..a0633d093 100644
--- a/controllers/class.RemoveFolder.php
+++ b/controllers/class.RemoveFolder.php
@@ -91,7 +91,7 @@ class SeedDMS_Controller_RemoveFolder extends SeedDMS_Controller_Common {
 			return false;
 		}
 
-		if(!$this->callHook('postRemoveFolder')) {
+		if(false === $this->callHook('postRemoveFolder')) {
 		}
 
 		return true;
diff --git a/controllers/class.TransferDocument.php b/controllers/class.TransferDocument.php
index 6585e3f0b..fcc1d8168 100644
--- a/controllers/class.TransferDocument.php
+++ b/controllers/class.TransferDocument.php
@@ -42,7 +42,7 @@ class SeedDMS_Controller_TransferDocument extends SeedDMS_Controller_Common {
 			if (!$document->transferToUser($newuser)) {
 				return false;
 			} else {
-				if(!$this->callHook('postTransferDocument')) {
+				if(false === $this->callHook('postTransferDocument')) {
 				}
 			}
 		}
diff --git a/controllers/class.UpdateDocument.php b/controllers/class.UpdateDocument.php
index 854fe1f60..4f6013256 100644
--- a/controllers/class.UpdateDocument.php
+++ b/controllers/class.UpdateDocument.php
@@ -88,7 +88,7 @@ class SeedDMS_Controller_UpdateDocument extends SeedDMS_Controller_Common {
 			}
 		}
 
-		if(!$this->callHook('postUpdateDocument', $document, $content)) {
+		if(false === $this->callHook('postUpdateDocument', $document, $content)) {
 		}
 
 		return $content;