Index: uspace/app/tester/print/print2.c
===================================================================
--- uspace/app/tester/print/print2.c	(revision de4f1654092789b6efed61bbff0da134b7746ec0)
+++ uspace/app/tester/print/print2.c	(revision 9c40b834b80ea3b3dd4beec40d348609791267f7)
@@ -62,4 +62,8 @@
 	TPRINTF("Real output:     [%td] [%tu] [%tx] [%ti] [%to]\n\n", d, neg_d, neg_d, d, neg_d);
 
+	TPRINTF("Testing printf(\"%%lf\", 768.0):\n");
+	TPRINTF("Expected output: [768.000000]\n");
+	TPRINTF("Real output:     [%lf]\n", 768.0);
+
 	return NULL;
 }
Index: uspace/lib/c/test/double_to_str.c
===================================================================
--- uspace/lib/c/test/double_to_str.c	(revision de4f1654092789b6efed61bbff0da134b7746ec0)
+++ uspace/lib/c/test/double_to_str.c	(revision 9c40b834b80ea3b3dd4beec40d348609791267f7)
@@ -176,4 +176,10 @@
 	PCUT_ASSERT_INT_EQUALS(-3, dec);
 	PCUT_ASSERT_STR_EQUALS("1100", buf);
+
+	d = extract_ieee_double(768.0);
+	ret = double_to_fixed_str(d, -1, 3, buf, size, &dec);
+	PCUT_ASSERT_INT_EQUALS(4, ret);
+	PCUT_ASSERT_INT_EQUALS(-3, dec);
+	PCUT_ASSERT_STR_EQUALS("768", buf);
 }