diff --git a/lib/krb5/test_store.c b/lib/krb5/test_store.c
index 4d7bbcb2d..61aa363b1 100644
--- a/lib/krb5/test_store.c
+++ b/lib/krb5/test_store.c
@@ -44,6 +44,8 @@ test_int8(krb5_context context, krb5_storage *sp)
 	0, 1, -1, 128, -127
     }, v;
 
+    krb5_storage_truncate(sp, 0);
+
     for (i = 0; i < sizeof(val[0])/sizeof(val); i++) {
 
 	ret = krb5_store_int8(sp, val[i]);
@@ -67,6 +69,8 @@ test_int16(krb5_context context, krb5_storage *sp)
 	0, 1, -1, 32768, -32767
     }, v;
 
+    krb5_storage_truncate(sp, 0);
+
     for (i = 0; i < sizeof(val[0])/sizeof(val); i++) {
 
 	ret = krb5_store_int16(sp, val[i]);
@@ -90,6 +94,8 @@ test_int32(krb5_context context, krb5_storage *sp)
 	0, 1, -1, 2147483647, -2147483646
     }, v;
 
+    krb5_storage_truncate(sp, 0);
+
     for (i = 0; i < sizeof(val[0])/sizeof(val); i++) {
 
 	ret = krb5_store_int32(sp, val[i]);
@@ -113,6 +119,8 @@ test_uint8(krb5_context context, krb5_storage *sp)
 	0, 1, 255
     }, v;
 
+    krb5_storage_truncate(sp, 0);
+
     for (i = 0; i < sizeof(val[0])/sizeof(val); i++) {
 
 	ret = krb5_store_uint8(sp, val[i]);
@@ -136,6 +144,8 @@ test_uint16(krb5_context context, krb5_storage *sp)
 	0, 1, 65535
     }, v;
 
+    krb5_storage_truncate(sp, 0);
+
     for (i = 0; i < sizeof(val[0])/sizeof(val); i++) {
 
 	ret = krb5_store_uint16(sp, val[i]);
@@ -159,6 +169,8 @@ test_uint32(krb5_context context, krb5_storage *sp)
 	0, 1, 4294967295UL
     }, v;
 
+    krb5_storage_truncate(sp, 0);
+
     for (i = 0; i < sizeof(val[0])/sizeof(val); i++) {
 
 	ret = krb5_store_uint32(sp, val[i]);