diff --git a/libregexp.c b/libregexp.c
index 2b33c86..1c519af 100644
--- a/libregexp.c
+++ b/libregexp.c
@@ -2433,6 +2433,17 @@ static int compute_stack_size(const uint8_t *bc_buf, int bc_buf_len)
     return stack_size_max;
 }
 
+static void *lre_bytecode_realloc(void *opaque, void *ptr, size_t size)
+{
+    if (size > (INT32_MAX / 2)) {
+        /* the bytecode cannot be larger than 2G. Leave some slack to 
+           avoid some overflows. */
+        return NULL;
+    } else {
+        return lre_realloc(opaque, ptr, size);
+    }
+}
+
 /* 'buf' must be a zero terminated UTF-8 string of length buf_len.
    Return NULL if error and allocate an error message in *perror_msg,
    otherwise the compiled bytecode and its length in plen.
@@ -2461,7 +2472,7 @@ uint8_t *lre_compile(int *plen, char *error_msg, int error_msg_size,
     s->total_capture_count = -1;
     s->has_named_captures = -1;
 
-    dbuf_init2(&s->byte_code, opaque, lre_realloc);
+    dbuf_init2(&s->byte_code, opaque, lre_bytecode_realloc);
     dbuf_init2(&s->group_names, opaque, lre_realloc);
 
     dbuf_put_u16(&s->byte_code, re_flags); /* first element is the flags */
diff --git a/quickjs.c b/quickjs.c
index b3fd19f..d4fd62a 100644
--- a/quickjs.c
+++ b/quickjs.c
@@ -1470,6 +1470,23 @@ static inline void js_dbuf_init(JSContext *ctx, DynBuf *s)
     dbuf_init2(s, ctx->rt, (DynBufReallocFunc *)js_realloc_rt);
 }
 
+static void *js_realloc_bytecode_rt(void *opaque, void *ptr, size_t size)
+{
+    JSRuntime *rt = opaque;
+    if (size > (INT32_MAX / 2)) {
+        /* the bytecode cannot be larger than 2G. Leave some slack to 
+           avoid some overflows. */
+        return NULL;
+    } else {
+        return rt->mf.js_realloc(&rt->malloc_state, ptr, size);
+    }
+}
+
+static inline void js_dbuf_bytecode_init(JSContext *ctx, DynBuf *s)
+{
+    dbuf_init2(s, ctx->rt, js_realloc_bytecode_rt);
+}
+
 static inline int is_digit(int c) {
     return c >= '0' && c <= '9';
 }
@@ -30809,7 +30826,7 @@ static JSFunctionDef *js_new_function_def(JSContext *ctx,
 
     fd->is_eval = is_eval;
     fd->is_func_expr = is_func_expr;
-    js_dbuf_init(ctx, &fd->byte_code);
+    js_dbuf_bytecode_init(ctx, &fd->byte_code);
     fd->last_opcode_pos = -1;
     fd->func_name = JS_ATOM_NULL;
     fd->var_object_idx = -1;
@@ -32904,7 +32921,7 @@ static __exception int resolve_variables(JSContext *ctx, JSFunctionDef *s)
 
     cc.bc_buf = bc_buf = s->byte_code.buf;
     cc.bc_len = bc_len = s->byte_code.size;
-    js_dbuf_init(ctx, &bc_out);
+    js_dbuf_bytecode_init(ctx, &bc_out);
 
     /* first pass for runtime checks (must be done before the
        variables are created) */
@@ -33524,7 +33541,7 @@ static __exception int resolve_labels(JSContext *ctx, JSFunctionDef *s)
 
     cc.bc_buf = bc_buf = s->byte_code.buf;
     cc.bc_len = bc_len = s->byte_code.size;
-    js_dbuf_init(ctx, &bc_out);
+    js_dbuf_bytecode_init(ctx, &bc_out);
 
 #if SHORT_OPCODES
     if (s->jump_size) {