diff --git a/lib/vquic/curl_ngtcp2.c b/lib/vquic/curl_ngtcp2.c
index 6467025137..575ebb9022 100644
--- a/lib/vquic/curl_ngtcp2.c
+++ b/lib/vquic/curl_ngtcp2.c
@@ -1212,7 +1212,7 @@ static CURLcode init_ngh3_conn(struct Curl_cfilter *cf,
   rc = nghttp3_conn_client_new(&ctx->h3conn,
                                &ngh3_callbacks,
                                &ctx->h3settings,
-                               nghttp3_mem_default(),
+                               Curl_nghttp3_mem(),
                                cf);
   if(rc) {
     failf(data, "error creating nghttp3 connection instance");
@@ -2475,7 +2475,7 @@ static const struct alpn_spec ALPN_SPEC_H3 = {
                               &ctx->connected_path,
                               NGTCP2_PROTO_VER_V1, &ng_callbacks,
                               &ctx->settings, &ctx->transport_params,
-                              NULL, cf);
+                              Curl_ngtcp2_mem(), cf);
   if(rc)
     return CURLE_QUIC_CONNECT_ERROR;
 
diff --git a/lib/vquic/curl_osslq.c b/lib/vquic/curl_osslq.c
index fa2c0a2899..3dd9753a72 100644
--- a/lib/vquic/curl_osslq.c
+++ b/lib/vquic/curl_osslq.c
@@ -1106,7 +1106,7 @@ static CURLcode cf_osslq_h3conn_init(struct cf_osslq_ctx *ctx, SSL *conn,
   rc = nghttp3_conn_client_new(&h3->conn,
                                &ngh3_callbacks,
                                &h3->settings,
-                               nghttp3_mem_default(),
+                               Curl_nghttp3_mem(),
                                user_data);
   if(rc) {
     result = CURLE_OUT_OF_MEMORY;
diff --git a/lib/vquic/vquic.c b/lib/vquic/vquic.c
index f8ce34129b..43a2c95021 100644
--- a/lib/vquic/vquic.c
+++ b/lib/vquic/vquic.c
@@ -724,6 +724,62 @@ CURLcode Curl_conn_may_http3(struct Curl_easy *data,
   return CURLE_OK;
 }
 
+#if defined(USE_NGTCP2) || defined(USE_NGHTTP3)
+
+static void *Curl_ngtcp2_malloc(size_t size, void *user_data)
+{
+  (void)user_data;
+  return Curl_cmalloc(size);
+}
+
+static void Curl_ngtcp2_free(void *ptr, void *user_data)
+{
+  (void)user_data;
+  Curl_cfree(ptr);
+}
+
+static void *Curl_ngtcp2_calloc(size_t nmemb, size_t size, void *user_data)
+{
+  (void)user_data;
+  return Curl_ccalloc(nmemb, size);
+}
+
+static void *Curl_ngtcp2_realloc(void *ptr, size_t size, void *user_data)
+{
+  (void)user_data;
+  return Curl_crealloc(ptr, size);
+}
+
+#ifdef USE_NGTCP2
+static struct ngtcp2_mem curl_ngtcp2_mem = {
+  NULL,
+  Curl_ngtcp2_malloc,
+  Curl_ngtcp2_free,
+  Curl_ngtcp2_calloc,
+  Curl_ngtcp2_realloc
+};
+struct ngtcp2_mem *Curl_ngtcp2_mem(void)
+{
+  return &curl_ngtcp2_mem;
+}
+#endif
+
+#ifdef USE_NGHTTP3
+static struct nghttp3_mem curl_nghttp3_mem = {
+  NULL,
+  Curl_ngtcp2_malloc,
+  Curl_ngtcp2_free,
+  Curl_ngtcp2_calloc,
+  Curl_ngtcp2_realloc
+};
+struct nghttp3_mem *Curl_nghttp3_mem(void)
+{
+  return &curl_nghttp3_mem;
+}
+#endif
+
+#endif /* USE_NGTCP2 || USE_NGHTTP3 */
+
 #else /* CURL_DISABLE_HTTP || !USE_HTTP3 */
 
 CURLcode Curl_conn_may_http3(struct Curl_easy *data,
diff --git a/lib/vquic/vquic_int.h b/lib/vquic/vquic_int.h
index d271368d29..38189beb70 100644
--- a/lib/vquic/vquic_int.h
+++ b/lib/vquic/vquic_int.h
@@ -91,4 +91,13 @@ CURLcode vquic_recv_packets(struct Curl_cfilter *cf,
 
 #endif /* !USE_HTTP3 */
 
+#ifdef USE_NGTCP2
+struct ngtcp2_mem;
+struct ngtcp2_mem *Curl_ngtcp2_mem(void);
+#endif
+#ifdef USE_NGHTTP3
+struct nghttp3_mem;
+struct nghttp3_mem *Curl_nghttp3_mem(void);
+#endif
+
 #endif /* HEADER_CURL_VQUIC_QUIC_INT_H */