diff --git a/drivers/staging/wlan-ng/prism2fw.c b/drivers/staging/wlan-ng/prism2fw.c
index 7d76a7f92a33..aaa70ed57710 100644
--- a/drivers/staging/wlan-ng/prism2fw.c
+++ b/drivers/staging/wlan-ng/prism2fw.c
@@ -439,7 +439,7 @@ void free_chunks(imgchunk_t *fchunk, unsigned int *nfchunks)
 		}
 	}
 	*nfchunks = 0;
-	memset(fchunk, 0, sizeof(fchunk));
+	memset(fchunk, 0, sizeof(*fchunk));
 
 }