diff --git a/doc/man3/SSL_CTX_set1_curves.pod b/doc/man3/SSL_CTX_set1_curves.pod
index a250f20c2206676606d5fe9d3fedbe1d1da1ee9b..2757ccb91d133a840f90ccce847b37e5e100aca9 100644
--- a/doc/man3/SSL_CTX_set1_curves.pod
+++ b/doc/man3/SSL_CTX_set1_curves.pod
@@ -32,6 +32,9 @@ SSL_set1_curves_list, SSL_get1_curves, SSL_get_shared_curve
 
 =head1 DESCRIPTION
 
+For all of the functions below that set the supported groups there must be at
+least one group in the list.
+
 SSL_CTX_set1_groups() sets the supported groups for B<ctx> to B<glistlen>
 groups in the array B<glist>. The array consist of all NIDs of groups in
 preference order. For a TLS client the groups are used directly in the
diff --git a/ssl/t1_lib.c b/ssl/t1_lib.c
index 156497988a622e3484fbca499fe307dbbcf9f2ec..b8b9fbda3900cb67da0d206db34279e98523a831 100644
--- a/ssl/t1_lib.c
+++ b/ssl/t1_lib.c
@@ -343,6 +343,10 @@ int tls1_set_groups(uint16_t **pext, size_t *pextlen,
      */
     unsigned long dup_list = 0;
 
+    if (ngroups == 0) {
+        SSLerr(SSL_F_TLS1_SET_GROUPS, SSL_R_BAD_LENGTH);
+        return 0;
+    }
     if ((glist = OPENSSL_malloc(ngroups * sizeof(*glist))) == NULL) {
         SSLerr(SSL_F_TLS1_SET_GROUPS, ERR_R_MALLOC_FAILURE);
         return 0;