7 files changed, 28 insertions, 8 deletions
diff --git a/mkspecs/common/msvc-desktop.conf b/mkspecs/common/msvc-desktop.conf
index 0b94e5a3f5..034fd3b305 100644
--- a/mkspecs/common/msvc-desktop.conf
+++ b/mkspecs/common/msvc-desktop.conf
@@ -19,6 +19,7 @@ CONFIG                 += flat debug_and_release debug_and_release_target precom
 # MSVC 2017 15.8+ fixed std::aligned_storage but compilation fails without
 # _ENABLE_EXTENDED_ALIGNED_STORAGE flag since the fix breaks binary compatibility.
 DEFINES                += UNICODE _UNICODE WIN32 _ENABLE_EXTENDED_ALIGNED_STORAGE
+DEFINES_RELEASE        += NDEBUG
 QMAKE_COMPILER_DEFINES += _WIN32
 contains(QMAKE_TARGET.arch, x86_64) {
     DEFINES += WIN64
diff --git a/mkspecs/common/winrt_winphone/qmake.conf b/mkspecs/common/winrt_winphone/qmake.conf
index 03fb96f2c5..e683018a81 100644
--- a/mkspecs/common/winrt_winphone/qmake.conf
+++ b/mkspecs/common/winrt_winphone/qmake.conf
@@ -11,6 +11,7 @@ CONFIG                  = package_manifest $$CONFIG incremental flat precompile_
 # MSVC 2017 15.8+ fixed std::aligned_storage but compilation fails without
 # _ENABLE_EXTENDED_ALIGNED_STORAGE flag since the fix breaks binary compatibility.
 DEFINES                += UNICODE WIN32 QT_LARGEFILE_SUPPORT Q_BYTE_ORDER=Q_LITTLE_ENDIAN _ENABLE_EXTENDED_ALIGNED_STORAGE
+DEFINES_RELEASE        += NDEBUG
 QMAKE_COMPILER_DEFINES += _WIN32
 
 DEPLOYMENT_PLUGIN      += qwinrt
diff --git a/mkspecs/features/default_pre.prf b/mkspecs/features/default_pre.prf
index 1c24bf071a..b2629d04c0 100644
--- a/mkspecs/features/default_pre.prf
+++ b/mkspecs/features/default_pre.prf
@@ -26,4 +26,10 @@ CONFIG = \
     unset(today)
 }
 
+CONFIG(debug, debug|release) {
+    DEFINES += $$DEFINES_DEBUG
+} else {
+    DEFINES += $$DEFINES_RELEASE
+}
+
 load(toolchain)
diff --git a/qmake/doc/src/qmake-manual.qdoc b/qmake/doc/src/qmake-manual.qdoc
index 3495f97b2c..a388b89477 100644
--- a/qmake/doc/src/qmake-manual.qdoc
+++ b/qmake/doc/src/qmake-manual.qdoc
@@ -1144,6 +1144,26 @@
 
     \snippet code/doc_src_qmake-manual.pro 27
 
+    \target DEFINES_DEBUG
+    \section1 DEFINES_DEBUG
+
+    Specifies preprocessor defines for the debug configuration. The values of
+    this variable get added to \l{DEFINES} before the project is loaded. This
+    variable is typically set in \l{#QMAKESPEC}{qmake.conf} and rarely needs
+    to be modified.
+
+    This variable was introduced in Qt 5.13.2.
+
+    \target DEFINES_RELEASE
+    \section1 DEFINES_RELEASE
+
+    Specifies preprocessor defines for the release configuration. The values of
+    this variable get added to \l{DEFINES} before the project is loaded. This
+    variable is typically set in \l{#QMAKESPEC}{qmake.conf} and rarely needs
+    to be modified.
+
+    This variable was introduced in Qt 5.13.2.
+
     \target DEF_FILE
     \section1 DEF_FILE
 
diff --git a/qmake/generators/win32/msvc_nmake.cpp b/qmake/generators/win32/msvc_nmake.cpp
index 63d89a5388..fd90cfcb2a 100644
--- a/qmake/generators/win32/msvc_nmake.cpp
+++ b/qmake/generators/win32/msvc_nmake.cpp
@@ -281,10 +281,6 @@ void NmakeMakefileGenerator::init()
     if (project->isActiveConfig("debug")) {
         project->values("QMAKE_CLEAN").append(targetBase + ".ilk");
         project->values("QMAKE_CLEAN").append(targetBase + ".idb");
-    } else {
-        ProStringList &defines = project->values("DEFINES");
-        if (!defines.contains("NDEBUG"))
-            defines.append("NDEBUG");
     }
 
     if (project->values("QMAKE_APP_FLAG").isEmpty() && project->isActiveConfig("dll")) {
diff --git a/qmake/generators/win32/msvc_objectmodel.cpp b/qmake/generators/win32/msvc_objectmodel.cpp
index 506229a7f4..5fb6bfb320 100644
--- a/qmake/generators/win32/msvc_objectmodel.cpp
+++ b/qmake/generators/win32/msvc_objectmodel.cpp
@@ -2125,7 +2125,6 @@ VCResourceCompilerTool::VCResourceCompilerTool()
         ShowProgress(linkProgressNotSet),
         SuppressStartupBanner(unset)
 {
-    PreprocessorDefinitions = QStringList("NDEBUG");
 }
 
 // VCDeploymentTool --------------------------------------------
diff --git a/qmake/generators/win32/msvc_vcproj.cpp b/qmake/generators/win32/msvc_vcproj.cpp
index b6f7f20564..df4876ace7 100644
--- a/qmake/generators/win32/msvc_vcproj.cpp
+++ b/qmake/generators/win32/msvc_vcproj.cpp
@@ -1038,9 +1038,6 @@ void VcprojGenerator::initConfiguration()
         initDeploymentTool();
     initWinDeployQtTool();
     initPreLinkEventTools();
-
-    if (!isDebug)
-        conf.compiler.PreprocessorDefinitions += "NDEBUG";
 }
 
 void VcprojGenerator::initCompilerTool()