diff --git a/.make-and-exec b/.make-and-exec
index 1993d30..0711f15 100755
--- a/.make-and-exec
+++ b/.make-and-exec
@@ -4,7 +4,7 @@
 # Making a symlink named foo-dbg causes it to compile foo.c with -DDEBUG.
 # To customise the compilation, you can set a CFLAGS env var before running foo.
 sourcename="${0%-dbg}.c"
-if [[ "$0" == *-dbg ]]; then opt='-O0 -DDEBUG'; else opt='-O3'; fi
+if [[ "$0" == *-dbg ]]; then opt='-Og -fsanitize=undefined,address -DDEBUG'; else opt='-O3'; fi
 targetfile="$(dirname "$0")/.make-and-exec-binaries/$(basename "$0")"
 if [[ ! -f "${targetfile}" || "${sourcename}" -nt "${targetfile}" ]]; then
 	mkdir -p "$(dirname "$0")/.make-and-exec-binaries"