diff --git a/lib/kadm5/chpass_s.c b/lib/kadm5/chpass_s.c
index 359f322df..1c3fbda2c 100644
--- a/lib/kadm5/chpass_s.c
+++ b/lib/kadm5/chpass_s.c
@@ -117,6 +117,7 @@ change(void *server_handle,
     } else {
 	HDB_extension ext;
 
+	memset(&ext, 0, sizeof (ext));
 	ext.data.element = choice_HDB_extension_data_hist_keys;
 	ext.data.u.hist_keys.len = 0;
 	ext.data.u.hist_keys.val = NULL;
@@ -228,6 +229,7 @@ kadm5_s_chpass_principal_with_key(void *server_handle,
     } else {
 	HDB_extension ext;
 
+	memset(&ext, 0, sizeof (ext));
 	ext.data.element = choice_HDB_extension_data_hist_keys;
 	ext.data.u.hist_keys.len = 0;
 	ext.data.u.hist_keys.val = NULL;
diff --git a/lib/kadm5/randkey_s.c b/lib/kadm5/randkey_s.c
index a83b3f48d..fd2342c8e 100644
--- a/lib/kadm5/randkey_s.c
+++ b/lib/kadm5/randkey_s.c
@@ -94,6 +94,7 @@ kadm5_s_randkey_principal(void *server_handle,
     } else {
 	HDB_extension ext;
 
+	memset(&ext, 0, sizeof (ext));
 	ext.data.element = choice_HDB_extension_data_hist_keys;
 	ext.data.u.hist_keys.len = 0;
 	ext.data.u.hist_keys.val = NULL;
diff --git a/lib/kadm5/set_keys.c b/lib/kadm5/set_keys.c
index 06ba35491..a5049a3fa 100644
--- a/lib/kadm5/set_keys.c
+++ b/lib/kadm5/set_keys.c
@@ -124,6 +124,7 @@ _kadm5_set_keys2(kadm5_server_context *context,
 
     memset(&keys, 0, sizeof (keys));
     memset(&hkset, 0, sizeof (hkset)); /* set set_time */
+    memset(&ext, 0, sizeof (ext));
     ext.data.element = choice_HDB_extension_data_hist_keys;
     memset(hist_keys, 0, sizeof (*hist_keys));