diff --git a/.github/workflows/CI-unixish.yml b/.github/workflows/CI-unixish.yml
index 07ee9731..9778f68a 100644
--- a/.github/workflows/CI-unixish.yml
+++ b/.github/workflows/CI-unixish.yml
@@ -44,10 +44,10 @@ jobs:
           sudo apt-get install valgrind
 
     - name: Install missing software on ubuntu (clang++)
-      if: matrix.os == 'ubuntu-24.04' && matrix.compiler == 'clang++'
+      if: contains(matrix.os, 'ubuntu') && matrix.compiler == 'clang++'
       run: |
         sudo apt-get update
-        sudo apt-get install libc++-18-dev
+        sudo apt-get install libc++-dev
 
       # coreutils contains "nproc"
     - name: Install missing software on macos
diff --git a/Makefile b/Makefile
index 7489ec83..b6bc26da 100644
--- a/Makefile
+++ b/Makefile
@@ -22,7 +22,7 @@ test:	testrunner	simplecpp
 	python3 -m pytest integration_test.py -vv
 
 selfcheck:	simplecpp
-	./selfcheck.sh
+	CXX=$(CXX) ./selfcheck.sh
 
 simplecpp:	main.o simplecpp.o
 	$(CXX) $(LDFLAGS) main.o simplecpp.o -o simplecpp
diff --git a/selfcheck.sh b/selfcheck.sh
index a43ef8c5..cc77981d 100755
--- a/selfcheck.sh
+++ b/selfcheck.sh
@@ -1,11 +1,111 @@
-#!/bin/sh
+#!/bin/bash
 
 output=$(./simplecpp simplecpp.cpp -e -f 2>&1)
 ec=$?
 errors=$(echo "$output" | grep -v 'Header not found: <')
 if [ $ec -ne 0 ]; then
-  # only fail if got errors which do not refer to missing system includes
+  # only fail if we got errors which do not refer to missing system includes
   if [ ! -z "$errors" ]; then
     exit $ec
   fi
-fi
\ No newline at end of file
+fi
+
+if [ -z "$CXX" ]; then
+  exit 0
+fi
+
+cxx_type=$($CXX --version | head -1 | cut -d' ' -f1)
+if [ "$cxx_type" = "Ubuntu" ] || [ "$cxx_type" = "Debian" ]; then
+  cxx_type=$($CXX --version | head -1 | cut -d' ' -f2)
+fi
+
+# TODO: generate defines from compiler
+if [ "$cxx_type" = "g++" ]; then
+  defs=
+  defs="$defs -D__GNUC__"
+  defs="$defs -D__STDC__"
+  defs="$defs -D__x86_64__"
+  defs="$defs -D__STDC_HOSTED__"
+  defs="$defs -D__CHAR_BIT__=8"
+  defs="$defs -D__has_builtin(x)=(1)"
+  defs="$defs -D__has_cpp_attribute(x)=(1)"
+  defs="$defs -D__has_attribute(x)=(1)"
+
+  inc=
+  while read line
+  do
+    inc="$inc -I$line"
+  done <<< "$($CXX -x c++ -v -c -S - 2>&1 < /dev/null | grep -e'^ [/A-Z]' | grep -v /cc1plus)"
+elif [ "$cxx_type" = "clang" ]; then
+  # libstdc++
+  defs=
+  defs="$defs -D__x86_64__"
+  defs="$defs -D__STDC_HOSTED__"
+  defs="$defs -D__CHAR_BIT__=8"
+  defs="$defs -D__has_builtin(x)=(1)"
+  defs="$defs -D__has_cpp_attribute(x)=(1)"
+  defs="$defs -D__has_feature(x)=(1)"
+  defs="$defs -D__has_include_next(x)=(0)"
+  defs="$defs -D__has_attribute(x)=(0)"
+  defs="$defs -D__building_module(x)=(0)"
+
+  inc=
+  while read line
+  do
+    inc="$inc -I$line"
+  done <<< "$($CXX -x c++ -v -c -S - 2>&1 < /dev/null | grep -e'^ [/A-Z]')"
+
+  # TODO: enable
+  # libc++
+  #defs=
+  #defs="$defs -D__x86_64__"
+  #defs="$defs -D__linux__"
+  #defs="$defs -D__SIZEOF_SIZE_T__=8"
+  #defs="$defs -D__has_include_next(x)=(0)"
+  #defs="$defs -D__has_builtin(x)=(1)"
+  #defs="$defs -D__has_feature(x)=(1)"
+
+  #inc=
+  #while read line
+  #do
+  #  inc="$inc -I$line"
+  #done <<< "$($CXX -x c++ -stdlib=libc++ -v -c -S - 2>&1 < /dev/null | grep -e'^ [/A-Z]')"
+elif [ "$cxx_type" = "Apple" ]; then
+  defs=
+  defs="$defs -D__BYTE_ORDER__"
+  defs="$defs -D__APPLE__"
+  defs="$defs -D__GNUC__=15"
+  defs="$defs -D__x86_64__"
+  defs="$defs -D__SIZEOF_SIZE_T__=8"
+  defs="$defs -D__LITTLE_ENDIAN__"
+  defs="$defs -D__has_feature(x)=(0)"
+  defs="$defs -D__has_extension(x)=(1)"
+  defs="$defs -D__has_attribute(x)=(0)"
+  defs="$defs -D__has_cpp_attribute(x)=(0)"
+  defs="$defs -D__has_include_next(x)=(0)"
+  defs="$defs -D__has_builtin(x)=(1)"
+  defs="$defs -D__is_target_os(x)=(0)"
+  defs="$defs -D__is_target_arch(x)=(0)"
+  defs="$defs -D__is_target_vendor(x)=(0)"
+  defs="$defs -D__is_target_environment(x)=(0)"
+  defs="$defs -D__is_target_variant_os(x)=(0)"
+  defs="$defs -D__is_target_variant_environment(x)=(0)"
+
+  inc=
+  while read line
+  do
+    inc="$inc -I$line"
+    # TODO: pass the framework path as such when possible
+  done <<< "$($CXX -x c++ -v -c -S - 2>&1 < /dev/null | grep -e'^ [/A-Z]' | sed 's/ (framework directory)//g')"
+  echo $inc
+else
+  echo "unknown compiler '$cxx_type'"
+  exit 1
+fi
+
+# run with -std=gnuc++* so __has_include(...) is available
+./simplecpp simplecpp.cpp -e -f -std=gnu++11 $defs $inc
+ec=$?
+if [ $ec -ne 0 ]; then
+  exit $ec
+fi