diff --git a/lib/vquic/curl_msh3.c b/lib/vquic/curl_msh3.c
index 6566447ba1..fe2a8c0ffe 100644
--- a/lib/vquic/curl_msh3.c
+++ b/lib/vquic/curl_msh3.c
@@ -642,10 +642,14 @@ static CURLcode cf_msh3_send(struct Curl_cfilter *cf, struct Curl_easy *data,
 
     for(i = 0; i < nheader; ++i) {
       struct dynhds_entry *e = Curl_dynhds_getn(&h2_headers, i);
-      nva[i].Name = e->name;
-      nva[i].NameLength = e->namelen;
-      nva[i].Value = e->value;
-      nva[i].ValueLength = e->valuelen;
+      if(e) {
+        nva[i].Name = e->name;
+        nva[i].NameLength = e->namelen;
+        nva[i].Value = e->value;
+        nva[i].ValueLength = e->valuelen;
+      }
+      else
+        memset(&nva[i], 0, sizeof(*nva));
     }
 
     CURL_TRC_CF(data, cf, "req: send %zu headers", nheader);
diff --git a/lib/vquic/curl_ngtcp2.c b/lib/vquic/curl_ngtcp2.c
index 052f280afc..9810a5fa5a 100644
--- a/lib/vquic/curl_ngtcp2.c
+++ b/lib/vquic/curl_ngtcp2.c
@@ -1506,11 +1506,15 @@ static CURLcode h3_stream_open(struct Curl_cfilter *cf,
 
   for(i = 0; i < nheader; ++i) {
     struct dynhds_entry *e = Curl_dynhds_getn(&h2_headers, i);
-    nva[i].name = (unsigned char *)e->name;
-    nva[i].namelen = e->namelen;
-    nva[i].value = (unsigned char *)e->value;
-    nva[i].valuelen = e->valuelen;
-    nva[i].flags = NGHTTP3_NV_FLAG_NONE;
+    if(e) {
+      nva[i].name = (unsigned char *)e->name;
+      nva[i].namelen = e->namelen;
+      nva[i].value = (unsigned char *)e->value;
+      nva[i].valuelen = e->valuelen;
+      nva[i].flags = NGHTTP3_NV_FLAG_NONE;
+    }
+    else
+      memset(&nva[i], 0, sizeof(*nva));
   }
 
   rc = ngtcp2_conn_open_bidi_stream(ctx->qconn, &sid, data);
diff --git a/lib/vquic/curl_osslq.c b/lib/vquic/curl_osslq.c
index 4026ffc392..ab7e341053 100644
--- a/lib/vquic/curl_osslq.c
+++ b/lib/vquic/curl_osslq.c
@@ -1914,11 +1914,15 @@ static ssize_t h3_stream_open(struct Curl_cfilter *cf,
 
   for(i = 0; i < nheader; ++i) {
     struct dynhds_entry *e = Curl_dynhds_getn(&h2_headers, i);
-    nva[i].name = (unsigned char *)e->name;
-    nva[i].namelen = e->namelen;
-    nva[i].value = (unsigned char *)e->value;
-    nva[i].valuelen = e->valuelen;
-    nva[i].flags = NGHTTP3_NV_FLAG_NONE;
+    if(e) {
+      nva[i].name = (unsigned char *)e->name;
+      nva[i].namelen = e->namelen;
+      nva[i].value = (unsigned char *)e->value;
+      nva[i].valuelen = e->valuelen;
+      nva[i].flags = NGHTTP3_NV_FLAG_NONE;
+    }
+    else
+      memset(&nva[i], 0, sizeof(*nva));
   }
 
   DEBUGASSERT(stream->s.id == -1);
diff --git a/lib/vquic/curl_quiche.c b/lib/vquic/curl_quiche.c
index 8a4243469b..51e4897401 100644
--- a/lib/vquic/curl_quiche.c
+++ b/lib/vquic/curl_quiche.c
@@ -1009,10 +1009,14 @@ static CURLcode h3_open_stream(struct Curl_cfilter *cf,
 
   for(i = 0; i < nheader; ++i) {
     struct dynhds_entry *e = Curl_dynhds_getn(&h2_headers, i);
-    nva[i].name = (unsigned char *)e->name;
-    nva[i].name_len = e->namelen;
-    nva[i].value = (unsigned char *)e->value;
-    nva[i].value_len = e->valuelen;
+    if(e) {
+      nva[i].name = (unsigned char *)e->name;
+      nva[i].name_len = e->namelen;
+      nva[i].value = (unsigned char *)e->value;
+      nva[i].value_len = e->valuelen;
+    }
+    else
+      memset(&nva[i], 0, sizeof(*nva));
   }
 
   *pnwritten = (size_t)nwritten;