diff --git a/qucs-activefilter/CMakeLists.txt b/qucs-activefilter/CMakeLists.txt
index 0a804cc5..1c315a7d 100644
--- a/qucs-activefilter/CMakeLists.txt
+++ b/qucs-activefilter/CMakeLists.txt
@@ -53,14 +53,27 @@ else()
 endif()
 
 
-set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
 
-if (MSVC)
-  add_compile_options(/Zc:__cplusplus /permissive- /MP /Zc:preprocessor)
-else()
-  # additional warnings
-  add_compile_options(-Wall -Wextra)
+if (CMAKE_BUILD_TYPE STREQUAL "Debug")
+    if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+        add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
+        add_compile_options(/Zc:__cplusplus  /MP /Zc:preprocessor /Od)
+    else()
+        add_compile_options(-Wall -Wextra -O0 -g)
+        if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+            add_compile_options(-Wno-ignored-attributes)
+        endif()
+    endif()
+elseif(CMAKE_BUILD_TYPE STREQUAL "Release")
+    if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+        add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
+        add_compile_options(/Zc:__cplusplus  /MP /Zc:preprocessor /Od /W0)
+    else()
+        add_compile_options(-w)
+    endif()
 endif()
 
 ADD_DEFINITIONS(${QT_DEFINITIONS})
diff --git a/qucs-attenuator/CMakeLists.txt b/qucs-attenuator/CMakeLists.txt
index 8d450762..218c6058 100644
--- a/qucs-attenuator/CMakeLists.txt
+++ b/qucs-attenuator/CMakeLists.txt
@@ -39,16 +39,29 @@ include_directories(
       ${Qt${QT_VERSION_MAJOR}Widgets_INCLUDE_DIRS}
       )
 
-
-set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
 
-if (MSVC)
-  add_compile_options(/Zc:__cplusplus /permissive- /MP /Zc:preprocessor)
-else()
-  # additional warnings
-  add_compile_options(-Wall -Wextra)
+if (CMAKE_BUILD_TYPE STREQUAL "Debug")
+  if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+      add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
+      add_compile_options(/Zc:__cplusplus  /MP /Zc:preprocessor /Od)
+  else()
+      add_compile_options(-Wall -Wextra -O0 -g)
+      if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+          add_compile_options(-Wno-ignored-attributes)
+      endif()
+  endif()
+elseif(CMAKE_BUILD_TYPE STREQUAL "Release")
+  if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+      add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
+      add_compile_options(/Zc:__cplusplus  /MP /Zc:preprocessor /Od /W0)
+  else()
+      add_compile_options(-w)
+  endif()
 endif()
+
 ADD_DEFINITIONS(${QT_DEFINITIONS})
 
 #ADD_SUBDIRECTORY( bitmaps ) -> added as resources
diff --git a/qucs-filter/CMakeLists.txt b/qucs-filter/CMakeLists.txt
index 07527ded..01f1c309 100644
--- a/qucs-filter/CMakeLists.txt
+++ b/qucs-filter/CMakeLists.txt
@@ -42,14 +42,27 @@ include_directories(
       )
 
 
-set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
 
-if (MSVC)
-  add_compile_options(/Zc:__cplusplus /permissive- /MP /Zc:preprocessor)
-else()
-  # additional warnings
-  add_compile_options(-Wall -Wextra)
+if (CMAKE_BUILD_TYPE STREQUAL "Debug")
+  if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+      add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
+      add_compile_options(/Zc:__cplusplus  /MP /Zc:preprocessor /Od)
+  else()
+      add_compile_options(-Wall -Wextra -O0 -g)
+      if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+          add_compile_options(-Wno-ignored-attributes)
+      endif()
+  endif()
+elseif(CMAKE_BUILD_TYPE STREQUAL "Release")
+  if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+      add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
+      add_compile_options(/Zc:__cplusplus  /MP /Zc:preprocessor /Od /W0)
+  else()
+      add_compile_options(-w)
+  endif()
 endif()
 
 ADD_DEFINITIONS(${QT_DEFINITIONS})
diff --git a/qucs-powercombining/CMakeLists.txt b/qucs-powercombining/CMakeLists.txt
index 7bc4fe48..a109e47c 100644
--- a/qucs-powercombining/CMakeLists.txt
+++ b/qucs-powercombining/CMakeLists.txt
@@ -51,15 +51,27 @@ else()
         )
 endif()
 
-
-set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
 
-if (MSVC)
- add_compile_options(/Zc:__cplusplus /permissive- /MP /Zc:preprocessor)
-else()
-  # additional warnings
-  add_compile_options(-Wall -Wextra)
+if (CMAKE_BUILD_TYPE STREQUAL "Debug")
+  if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+      add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
+      add_compile_options(/Zc:__cplusplus  /MP /Zc:preprocessor /Od)
+  else()
+      add_compile_options(-Wall -Wextra -O0 -g)
+      if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+          add_compile_options(-Wno-ignored-attributes)
+      endif()
+  endif()
+elseif(CMAKE_BUILD_TYPE STREQUAL "Release")
+  if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+      add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
+      add_compile_options(/Zc:__cplusplus  /MP /Zc:preprocessor /Od /W0)
+  else()
+      add_compile_options(-w)
+  endif()
 endif()
 
 ADD_DEFINITIONS(${QT_DEFINITIONS})
diff --git a/qucs-transcalc/CMakeLists.txt b/qucs-transcalc/CMakeLists.txt
index 21b62d1b..c89a2e93 100644
--- a/qucs-transcalc/CMakeLists.txt
+++ b/qucs-transcalc/CMakeLists.txt
@@ -41,14 +41,27 @@ include_directories(
       )
 
 
-set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD 20)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
 
-if (MSVC)
-  add_compile_options(/Zc:__cplusplus /permissive- /MP /Zc:preprocessor)
+if (CMAKE_BUILD_TYPE STREQUAL "Debug")
+if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+    add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
+    add_compile_options(/Zc:__cplusplus  /MP /Zc:preprocessor /Od)
 else()
-  # additional warnings
-  add_compile_options(-Wall -Wextra)
+    add_compile_options(-Wall -Wextra -O0 -g)
+    if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+        add_compile_options(-Wno-ignored-attributes)
+    endif()
+endif()
+elseif(CMAKE_BUILD_TYPE STREQUAL "Release")
+if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+    add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
+    add_compile_options(/Zc:__cplusplus  /MP /Zc:preprocessor /Od /W0)
+else()
+    add_compile_options(-w)
+endif()
 endif()
 
 ADD_DEFINITIONS(${QT_DEFINITIONS})
diff --git a/qucs/CMakeLists.txt b/qucs/CMakeLists.txt
index cbae80c3..db59bffe 100755
--- a/qucs/CMakeLists.txt
+++ b/qucs/CMakeLists.txt
@@ -85,14 +85,28 @@ set(CMAKE_AUTOUIC ON)
 set(CMAKE_AUTOMOC ON)
 set(CMAKE_AUTORCC ON)
 ENDIF()
-set(CMAKE_CXX_STANDARD 17)
-set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
-if (MSVC)
-    add_compile_options(/Zc:__cplusplus /permissive- /MP /Zc:preprocessor)
-else()
-    # additional warnings
-    add_compile_options(-Wall -Wextra)
+set(CMAKE_CXX_STANDARD 20)
+set(CMAKE_CXX_STANDARD_REQUIRED ON)
+set(CMAKE_CXX_EXTENSIONS OFF)
+
+if (CMAKE_BUILD_TYPE STREQUAL "Debug")
+    if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+        add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
+        add_compile_options(/Zc:__cplusplus  /MP /Zc:preprocessor /Od)
+    else()
+        add_compile_options(-Wall -Wextra -O0 -g)
+        if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
+            add_compile_options(-Wno-ignored-attributes)
+        endif()
+    endif()
+elseif(CMAKE_BUILD_TYPE STREQUAL "Release")
+    if (CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
+        add_compile_definitions(_CRT_SECURE_NO_WARNINGS)
+        add_compile_options(/Zc:__cplusplus  /MP /Zc:preprocessor /Od /W0)
+    else()
+        add_compile_options(-w)
+    endif()
 endif()
 
 INCLUDE_DIRECTORIES(