kc3-lang/kc3

diff --git a/config.subr b/config.subr
index 6c09431..8cd4a8d 100644
--- a/config.subr
+++ b/config.subr
@@ -175,6 +175,7 @@ config_asan() {
     OUT_C=".config_$NAME.c"
     OUT=".config_$NAME"
     echo "/* generated by configure */" > "$OUT_C"
+    echo "#include <stdlib.h>" >> "$OUT_C"
     echo "int main (void) { malloc(1); return 0; }" >> "$OUT_C"
     if $LIBTOOL --tag CC --mode link ${CC} ${CPPFLAGS} ${CFLAGS} \
                 -fsanitize=address -fno-omit-frame-pointer \