diff --git a/ssl/ssl_sess.c b/ssl/ssl_sess.c
index 0ea74389c2ac7abb97cd0a31669e1b2400182395..c6d5c1247f92e791f694243416ea018346bb6447 100644
--- a/ssl/ssl_sess.c
+++ b/ssl/ssl_sess.c
@@ -678,6 +678,15 @@ int SSL_CTX_add_session(SSL_CTX *ctx, SSL_SESSION *c)
          * obtain the same session from an external cache)
          */
         s = NULL;
+    } else if (s == NULL &&
+               lh_SSL_SESSION_retrieve(ctx->sessions, c) == NULL) {
+        /* s == NULL can also mean OOM error in lh_SSL_SESSION_insert ... */
+
+        /*
+         * ... so take back the extra reference and also don't add
+         * the session to the SSL_SESSION_list at this time
+         */
+        s = c;
     }
 
     /* Put at the head of the queue unless it is already in the cache */