Index: uspace/app/dplay/wave.c
===================================================================
--- uspace/app/dplay/wave.c	(revision c0149cc54ea29b8721df635059d2eb7364bf9936)
+++ uspace/app/dplay/wave.c	(revision af054290060026df3acb2f8ef009f1ddcda92366)
@@ -43,7 +43,7 @@
     bool *sign, const char **error)
 {
-	if (!file || !data || !data_size) {
+	if (!file) {
 		if (error)
-			*error = "file, data and data_size must be specified";
+			*error = "file not present";
 		return EINVAL;
 	}
@@ -86,6 +86,8 @@
 	}
 
-	*data = header->data;
-	*data_size = uint32_t_le2host(header->subchunk2_size);
+	if (data)
+		*data = header->data;
+	if (data_size)
+		*data_size = uint32_t_le2host(header->subchunk2_size);
 
 	if (sampling_rate)