diff --git a/keyimport.c b/keyimport.c
index 272fcceebc0808b933745c4ac8c42902803d0ce0..6f2634fa4530d2b071f7128924114b4a2ca9c19a 100644
--- a/keyimport.c
+++ b/keyimport.c
@@ -810,7 +810,7 @@ static sign_key *openssh_read(const char *filename, char * UNUSED(passphrase))
 	}
 	m_burn(key->keyblob, key->keyblob_size);
 	m_free(key->keyblob);
-	m_burn(key, sizeof(key));
+	m_burn(key, sizeof(*key));
 	m_free(key);
 	if (errmsg) {
 		fprintf(stderr, "Error: %s\n", errmsg);