diff --git a/manifests/config.pp b/manifests/config.pp
index 564fc8f2d..e906ca4b9 100644
--- a/manifests/config.pp
+++ b/manifests/config.pp
@@ -13,7 +13,7 @@
 #
 class icinga2::config {
 
-  if defined($caller_module_name) and $module_name != $caller_module_name {
+  if !defined($caller_module_name) or $module_name != $caller_module_name {
     fail("icinga2::config is a private class of the module icinga2, you're not permitted to use it.")
   }
 
diff --git a/manifests/debian/dbconfig.pp b/manifests/debian/dbconfig.pp
index 24ab14fc1..79aa9f857 100644
--- a/manifests/debian/dbconfig.pp
+++ b/manifests/debian/dbconfig.pp
@@ -8,7 +8,7 @@
   $ssl = false,
 ) {
 
-  if defined($caller_module_name) and $module_name != $caller_module_name and $caller_module_name != '' {
+  if !defined($caller_module_name) or $module_name != $caller_module_name {
     fail("icinga2::debian::dbconfig is a private define resource of the module icinga2, you're not permitted to use it.")
   }
 
diff --git a/manifests/feature.pp b/manifests/feature.pp
index b50ec2afa..5b007f008 100644
--- a/manifests/feature.pp
+++ b/manifests/feature.pp
@@ -8,7 +8,7 @@
   $feature = $title,
 ) {
 
-  if defined($caller_module_name) and $module_name != $caller_module_name and $caller_module_name != '' {
+  if !defined($caller_module_name) or $module_name != $caller_module_name {
     fail("icinga2::feature is a private define resource of the module icinga2, you're not permitted to use it.")
   }
 
diff --git a/manifests/install.pp b/manifests/install.pp
index 3d0c9d278..76075dc60 100644
--- a/manifests/install.pp
+++ b/manifests/install.pp
@@ -14,7 +14,7 @@
 #
 class icinga2::install {
 
-  if defined($caller_module_name) and $module_name != $caller_module_name {
+  if !defined($caller_module_name) or $module_name != $caller_module_name {
     fail("icinga2::install is a private class of the module icinga2, you're not permitted to use it.")
   }
 
diff --git a/manifests/object.pp b/manifests/object.pp
index 6c356de3c..d82ea9ab4 100644
--- a/manifests/object.pp
+++ b/manifests/object.pp
@@ -77,7 +77,7 @@
   $attrs        = {},
 ) {
 
-  if defined($caller_module_name) and $module_name != $caller_module_name and $caller_module_name != '' {
+  if !defined($caller_module_name) or $module_name != $caller_module_name {
     fail("icinga2::object is a private define resource of the module icinga2, you're not permitted to use it.")
   }
 
diff --git a/manifests/repo.pp b/manifests/repo.pp
index 4fd01a86c..90b2f15dc 100644
--- a/manifests/repo.pp
+++ b/manifests/repo.pp
@@ -16,7 +16,7 @@
 #
 class icinga2::repo {
 
-  if defined($caller_module_name) and $module_name != $caller_module_name {
+  if !defined($caller_module_name) or $module_name != $caller_module_name {
     fail("icinga2::repo is a private class of the module icinga2, you're not permitted to use it.")
   }
 
diff --git a/manifests/service.pp b/manifests/service.pp
index 04c664b2b..b3c38cb76 100644
--- a/manifests/service.pp
+++ b/manifests/service.pp
@@ -16,7 +16,7 @@
 #
 class icinga2::service {
 
-  if defined($caller_module_name) and $module_name != $caller_module_name {
+  if !defined($caller_module_name) or $module_name != $caller_module_name {
     fail("icinga2::service is a private class of the module icinga2, you're not permitted to use it.")
   }