diff --git a/Samples/5_Domain_Specific/simpleVulkan/main.cpp b/Samples/5_Domain_Specific/simpleVulkan/main.cpp
index 2419220e..ecce8868 100644
--- a/Samples/5_Domain_Specific/simpleVulkan/main.cpp
+++ b/Samples/5_Domain_Specific/simpleVulkan/main.cpp
@@ -38,7 +38,7 @@
 typedef float vec2[2];
 std::string   execution_path;
 
-#ifndef NDEBUG
+#ifdef NDEBUG
 #define ENABLE_VALIDATION (false)
 #else
 #define ENABLE_VALIDATION (true)
diff --git a/Samples/5_Domain_Specific/simpleVulkanMMAP/main.cpp b/Samples/5_Domain_Specific/simpleVulkanMMAP/main.cpp
index 3f84d5ea..879559f7 100644
--- a/Samples/5_Domain_Specific/simpleVulkanMMAP/main.cpp
+++ b/Samples/5_Domain_Specific/simpleVulkanMMAP/main.cpp
@@ -44,7 +44,7 @@
 #include "helper_multiprocess.h"
 
 // #define DEBUG
-#ifndef DEBUG
+#ifdef NDEBUG
 #define ENABLE_VALIDATION (false)
 #else
 #define ENABLE_VALIDATION (true)
diff --git a/Samples/5_Domain_Specific/vulkanImageCUDA/vulkanImageCUDA.cu b/Samples/5_Domain_Specific/vulkanImageCUDA/vulkanImageCUDA.cu
index f991da41..51920a77 100644
--- a/Samples/5_Domain_Specific/vulkanImageCUDA/vulkanImageCUDA.cu
+++ b/Samples/5_Domain_Specific/vulkanImageCUDA/vulkanImageCUDA.cu
@@ -69,9 +69,9 @@ const int MAX_FRAMES = 4;
 const std::vector<const char *> validationLayers = {"VK_LAYER_KHRONOS_validation"};
 
 #ifdef NDEBUG
-const bool enableValidationLayers = true;
-#else
 const bool enableValidationLayers = false;
+#else
+const bool enableValidationLayers = true;
 #endif
 
 std::string execution_path;