diff --git a/.gitignore b/.gitignore
index f4906c0d..09b55f86 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,4 +7,5 @@ example/cancel
 example/cancel_connect
 tests/env
 tests/create
+tests/sleep
 tests/wait
diff --git a/tests/makefile b/tests/makefile
index 1b90f102..bbb23c14 100644
--- a/tests/makefile
+++ b/tests/makefile
@@ -4,12 +4,14 @@ CFLAGS     = -I. -Wall -g -O0 -I../machinarium
 LFLAGS_LIB = ../machinarium/libmachinarium.a
 LFLAGS_LIB_UV = ~/temp/libuv/.libs/libuv.a -pthread
 LFLAGS     = $(LFLAGS_LIB) $(LFLAGS_LIB_UV)
-TESTS      = env create wait
+TESTS      = env create sleep wait
 all: validate clean $(TESTS)
 env:
 	$(CC) $(CFLAGS) env.c $(LFLAGS) -o env
 create:
 	$(CC) $(CFLAGS) create.c $(LFLAGS) -o create
+sleep:
+	$(CC) $(CFLAGS) sleep.c $(LFLAGS) -o sleep
 wait:
 	$(CC) $(CFLAGS) wait.c $(LFLAGS) -o wait
 validate:
diff --git a/tests/sleep.c b/tests/sleep.c
new file mode 100644
index 00000000..fa547a4e
--- /dev/null
+++ b/tests/sleep.c
@@ -0,0 +1,31 @@
+
+/*
+ * machinarium.
+ *
+ * Cooperative multitasking engine.
+*/
+
+#include <machinarium.h>
+#include <assert.h>
+
+static void
+test_child(void *arg)
+{
+	mm_t env = arg;
+	printf("child started\n");
+	printf("sleep 10 ms\n");
+	mm_sleep(env, 10);
+	printf("sleep wakeup\n");
+	printf("child ended\n");
+	mm_stop(env);
+}
+
+int
+main(int argc, char *argv[])
+{
+	mm_t env = mm_new();
+	mm_create(env, test_child, env);
+	mm_start(env);
+	mm_free(env);
+	return 0;
+}