diff --git a/apps/s_client.c b/apps/s_client.c
index fa91eece02168fbe876b563496715b06b29a495f..723e7cba3b88b9b518b074de1b4d01b17f3cdd90 100644
--- a/apps/s_client.c
+++ b/apps/s_client.c
@@ -160,6 +160,7 @@ typedef unsigned int u_int;
 #include <openssl/rand.h>
 #include <openssl/ocsp.h>
 #include <openssl/bn.h>
+#include <openssl/async.h>
 #ifndef OPENSSL_NO_SRP
 # include <openssl/srp.h>
 #endif
@@ -1205,8 +1206,10 @@ int s_client_main(int argc, char **argv)
         goto end;
     }
 
-    if (async)
+    if (async) {
         SSL_CTX_set_mode(ctx, SSL_MODE_ASYNC);
+        ASYNC_init_pool(0, 0);
+    }
 
     if (!config_ctx(cctx, ssl_args, ctx, 1, jpake_secret == NULL))
         goto end;
@@ -2096,6 +2099,9 @@ int s_client_main(int argc, char **argv)
             print_stuff(bio_c_out, con, 1);
         SSL_free(con);
     }
+    if (async) {
+        ASYNC_free_pool();
+    }
 #if !defined(OPENSSL_NO_NEXTPROTONEG)
     OPENSSL_free(next_proto.data);
 #endif