diff --git a/extmod/re1.5/re1.5.h b/extmod/re1.5/re1.5.h
index 815c5d33d1..ba6f97b743 100644
--- a/extmod/re1.5/re1.5.h
+++ b/extmod/re1.5/re1.5.h
@@ -48,6 +48,9 @@ void printre(Regexp*);
 #ifndef re1_5_fatal
 void re1_5_fatal(char*);
 #endif
+#ifndef re1_5_stack_chk
+#define re1_5_stack_chk()
+#endif
 void *mal(int);
 
 struct Prog
diff --git a/extmod/re1.5/recursiveloop.c b/extmod/re1.5/recursiveloop.c
index e8fef03049..bb337decfb 100644
--- a/extmod/re1.5/recursiveloop.c
+++ b/extmod/re1.5/recursiveloop.c
@@ -9,7 +9,9 @@ recursiveloop(char *pc, const char *sp, Subject *input, const char **subp, int n
 {
 	const char *old;
 	int off;
-	
+
+	re1_5_stack_chk();
+
 	for(;;) {
 		if(inst_is_consumer(*pc)) {
 			// If we need to match a character, but there's none left, it's fail