diff --git a/tests/manual/test.c b/tests/manual/test.c
index 1b69c64..681caf7 100644
--- a/tests/manual/test.c
+++ b/tests/manual/test.c
@@ -1,36 +1,36 @@
 /*
  * Copyright 2014-2017 Milian Wolff <mail@milianw.de>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
 #include <unistd.h>
 #include <stdlib.h>
 #include <stdio.h>
 
 int main()
 {
     int i;
     // make app deterministic
     srand(0);
     void* p = malloc(1);
     for (i = 0; i < 10000; ++i) {
-        malloc(rand() % 1000);
+        void* __attribute__((unused)) l = malloc(rand() % 1000);
         usleep(100);
     }
     printf("malloc: %p\n", p);
     free(p);
     return 0;
 }
diff --git a/tests/manual/test.cpp b/tests/manual/test.cpp
index ecf4c0a..dd70a00 100644
--- a/tests/manual/test.cpp
+++ b/tests/manual/test.cpp
@@ -1,115 +1,115 @@
 /*
  * Copyright 2014-2017 Milian Wolff <mail@milianw.de>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
 #include <cstdio>
 #include <cstdlib>
 
 #include "util/config.h"
 
 #if defined(_ISOC11_SOURCE)
 #define HAVE_ALIGNED_ALLOC 1
 #else
 #define HAVE_ALIGNED_ALLOC 0
 #endif
 
 struct Foo
 {
     Foo()
         : i(new int)
     {
     }
     ~Foo()
     {
         delete i;
     }
     int* i;
 };
 
 void asdf()
 {
     int* i = new int;
     printf("i in asdf: %p\n", (void*)i);
 }
 
 void bar()
 {
     asdf();
 }
 
 void laaa()
 {
     bar();
 }
 
 void split()
 {
     Foo f;
     asdf();
     bar();
     laaa();
 }
 
 static Foo foo;
 
 int main()
 {
     Foo* f = new Foo;
     printf("new Foo: %p\n", (void*)f);
     delete f;
 
     char* c = new char[1000];
     printf("new char[]: %p\n", (void*)c);
     delete[] c;
 
     void* buf = malloc(100);
     printf("malloc: %p\n", buf);
     buf = realloc(buf, 200);
     printf("realloc: %p\n", buf);
     free(buf);
 
     buf = calloc(5, 5);
     printf("calloc: %p\n", buf);
 #if HAVE_CFREE
     cfree(buf);
 #else
     free(buf);
 #endif
 
 #if HAVE_ALIGNED_ALLOC
     buf = aligned_alloc(16, 160);
     printf("aligned_alloc: %p\n", buf);
     free(buf);
 #endif
 
     buf = valloc(32);
     printf("valloc: %p\n", buf);
     free(buf);
 
-    posix_memalign(&buf, 16, 64);
+    int __attribute__((unused)) ret = posix_memalign(&buf, 16, 64);
     printf("posix_memalign: %p\n", buf);
     free(buf);
 
     for (int i = 0; i < 10; ++i) {
         laaa();
     }
     laaa();
 
     split();
 
     return 0;
 }