diff --git a/tools/TInspectorEXE/CMakeLists.txt b/tools/TInspectorEXE/CMakeLists.txt
index 3aa2537e2f..2ebcc6e40a 100644
--- a/tools/TInspectorEXE/CMakeLists.txt
+++ b/tools/TInspectorEXE/CMakeLists.txt
@@ -5,3 +5,8 @@ set (EXECUTABLE_PROJECT ON)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit)
 unset (EXECUTABLE_PROJECT)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
+
+# This project depends from Qt.
+# Qt 5.11.2 is incompatible with c++20.
+# So, it should be compiled with c++11/c++14 language standard.
+set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 11)
diff --git a/tools/TKDFBrowser/CMakeLists.txt b/tools/TKDFBrowser/CMakeLists.txt
index 29b45e9843..a2a5445156 100644
--- a/tools/TKDFBrowser/CMakeLists.txt
+++ b/tools/TKDFBrowser/CMakeLists.txt
@@ -3,3 +3,8 @@ project(TKDFBrowser)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
+
+# This project depends from Qt.
+# Qt 5.11.2 is incompatible with c++20.
+# So, it should be compiled with c++11/c++14 language standard.
+set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 11)
diff --git a/tools/TKMessageModel/CMakeLists.txt b/tools/TKMessageModel/CMakeLists.txt
index 911ffb1fbe..a6ef727d9e 100644
--- a/tools/TKMessageModel/CMakeLists.txt
+++ b/tools/TKMessageModel/CMakeLists.txt
@@ -3,3 +3,8 @@ project(TKMessageModel)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
+
+# This project depends from Qt.
+# Qt 5.11.2 is incompatible with c++20.
+# So, it should be compiled with c++11/c++14 language standard.
+set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 11)
diff --git a/tools/TKMessageView/CMakeLists.txt b/tools/TKMessageView/CMakeLists.txt
index 9b3c1aaec7..ee948ecc72 100644
--- a/tools/TKMessageView/CMakeLists.txt
+++ b/tools/TKMessageView/CMakeLists.txt
@@ -3,3 +3,8 @@ project(TKMessageView)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
+
+# This project depends from Qt.
+# Qt 5.11.2 is incompatible with c++20.
+# So, it should be compiled with c++11/c++14 language standard.
+set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 11)
diff --git a/tools/TKShapeView/CMakeLists.txt b/tools/TKShapeView/CMakeLists.txt
index 928a72f1e8..c4dd2e935b 100644
--- a/tools/TKShapeView/CMakeLists.txt
+++ b/tools/TKShapeView/CMakeLists.txt
@@ -3,3 +3,8 @@ project(TKShapeView)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
+
+# This project depends from Qt.
+# Qt 5.11.2 is incompatible with c++20.
+# So, it should be compiled with c++11/c++14 language standard.
+set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 11)
diff --git a/tools/TKTInspector/CMakeLists.txt b/tools/TKTInspector/CMakeLists.txt
index 0a05b7ca15..23389b74cd 100644
--- a/tools/TKTInspector/CMakeLists.txt
+++ b/tools/TKTInspector/CMakeLists.txt
@@ -6,4 +6,9 @@ OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
 
+# This project depends from Qt.
+# Qt 5.11.2 is incompatible with c++20.
+# So, it should be compiled with c++11/c++14 language standard.
+set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 11)
+
 unset (INSTALL_API)
diff --git a/tools/TKTInspectorAPI/CMakeLists.txt b/tools/TKTInspectorAPI/CMakeLists.txt
index d2f21e0f9b..06b3798301 100644
--- a/tools/TKTInspectorAPI/CMakeLists.txt
+++ b/tools/TKTInspectorAPI/CMakeLists.txt
@@ -6,5 +6,9 @@ OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
 
-UNSET (TOOL_API_LIBRARY)
+# This project depends from Qt.
+# Qt 5.11.2 is incompatible with c++20.
+# So, it should be compiled with c++11/c++14 language standard.
+set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 11)
 
+UNSET (TOOL_API_LIBRARY)
diff --git a/tools/TKToolsDraw/CMakeLists.txt b/tools/TKToolsDraw/CMakeLists.txt
index f57982cf05..d448d51881 100644
--- a/tools/TKToolsDraw/CMakeLists.txt
+++ b/tools/TKToolsDraw/CMakeLists.txt
@@ -3,3 +3,8 @@ project(TKToolsDraw)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
+
+# This project depends from Qt.
+# Qt 5.11.2 is incompatible with c++20.
+# So, it should be compiled with c++11/c++14 language standard.
+set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 11)
diff --git a/tools/TKTreeModel/CMakeLists.txt b/tools/TKTreeModel/CMakeLists.txt
index 99fc025494..0b2d9c65eb 100644
--- a/tools/TKTreeModel/CMakeLists.txt
+++ b/tools/TKTreeModel/CMakeLists.txt
@@ -3,3 +3,8 @@ project(TKTreeModel)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
+
+# This project depends from Qt.
+# Qt 5.11.2 is incompatible with c++20.
+# So, it should be compiled with c++11/c++14 language standard.
+set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 11)
diff --git a/tools/TKVInspector/CMakeLists.txt b/tools/TKVInspector/CMakeLists.txt
index 1a6de1456a..cbe9037f6d 100644
--- a/tools/TKVInspector/CMakeLists.txt
+++ b/tools/TKVInspector/CMakeLists.txt
@@ -3,3 +3,8 @@ project(TKVInspector)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
+
+# This project depends from Qt.
+# Qt 5.11.2 is incompatible with c++20.
+# So, it should be compiled with c++11/c++14 language standard.
+set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 11)
diff --git a/tools/TKView/CMakeLists.txt b/tools/TKView/CMakeLists.txt
index ed33343886..d630f5bbe3 100644
--- a/tools/TKView/CMakeLists.txt
+++ b/tools/TKView/CMakeLists.txt
@@ -3,3 +3,8 @@ project(TKView)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit)
 OCCT_INCLUDE_CMAKE_FILE (adm/cmake/occt_toolkit_prepare_tool)
+
+# This project depends from Qt.
+# Qt 5.11.2 is incompatible with c++20.
+# So, it should be compiled with c++11/c++14 language standard.
+set_property(TARGET ${PROJECT_NAME} PROPERTY CXX_STANDARD 11)