diff --git a/Meta/check-debug-flags.sh b/Meta/check-debug-flags.sh
index 862b4176048..cf6746c2db9 100755
--- a/Meta/check-debug-flags.sh
+++ b/Meta/check-debug-flags.sh
@@ -11,7 +11,7 @@ while IFS= read -r FLAG; do
     # We simply search whether the CMakeLists.txt *ever* sets the flag.
     # There are (basically) no false positives, but there might be false negatives,
     # for example we intentionally don't check for commented-out lines here.
-    if ! grep -qP "add_compile_definitions\(\"${FLAG}" Meta/CMake/all_the_debug_macros.cmake ; then
+    if ! grep -qP "set\(${FLAG}" Meta/CMake/all_the_debug_macros.cmake ; then
         echo "ALL_THE_DEBUG_MACROS probably doesn't include ${FLAG}"
         MISSING_FLAGS=y
     fi
@@ -19,6 +19,7 @@ done < <(
     git ls-files -- \
         '*.cpp' \
         '*.h' \
+        '*.in' \
         ':!:Kernel/FileSystem/ext2_fs.h' \
         ':!:Userland/Libraries/LibELF/exec_elf.h' \
     | xargs grep -P '^ *#.*DEBUG' \