diff --git a/cmd/zdb/zdb.c b/cmd/zdb/zdb.c
index 468fbbb2cf..9d27a984e0 100644
--- a/cmd/zdb/zdb.c
+++ b/cmd/zdb/zdb.c
@@ -868,8 +868,8 @@ dump_history(spa_t *spa)
 			(void) snprintf(internalstr,
 			    sizeof (internalstr),
 			    "[internal %s txg:%lld] %s",
-			    zfs_history_event_names[ievent], txg,
-			    intstr);
+			    zfs_history_event_names[ievent],
+			    (longlong_t)txg, intstr);
 			cmd = internalstr;
 		}
 		tsec = time;
diff --git a/cmd/ztest/ztest.c b/cmd/ztest/ztest.c
index 9481d3f07a..47b360721a 100644
--- a/cmd/ztest/ztest.c
+++ b/cmd/ztest/ztest.c
@@ -2019,7 +2019,7 @@ ztest_od_init(ztest_od_t *od, uint64_t id, char *tag, uint64_t index,
 	od->od_gen = 0;
 
 	(void) snprintf(od->od_name, sizeof (od->od_name), "%s(%lld)[%llu]",
-	    tag, (int64_t)id, index);
+	    tag, (longlong_t)id, (u_longlong_t)index);
 }
 
 /*
@@ -3919,7 +3919,7 @@ ztest_fzap(ztest_ds_t *zd, uint64_t id)
 		int error;
 
 		(void) snprintf(name, sizeof (name), "fzap-%llu-%llu",
-		    id, value);
+		    (u_longlong_t)id, (u_longlong_t)value);
 
 		tx = dmu_tx_create(os);
 		dmu_tx_hold_zap(tx, object, B_TRUE, name);
diff --git a/lib/libzfs/libzfs_pool.c b/lib/libzfs/libzfs_pool.c
index 197d81ccaa..a0309b8764 100644
--- a/lib/libzfs/libzfs_pool.c
+++ b/lib/libzfs/libzfs_pool.c
@@ -1230,7 +1230,7 @@ zpool_rewind_exclaim(libzfs_handle_t *hdl, const char *name, boolean_t dryrun,
 	(void) nvlist_lookup_int64(rbi, ZPOOL_CONFIG_REWIND_TIME, &loss);
 
 	if (localtime_r((time_t *)&rewindto, &t) != NULL &&
-	    strftime(timestr, 128, 0, &t) != 0) {
+	    strftime(timestr, 128, "%c", &t) != 0) {
 		if (dryrun) {
 			(void) printf(dgettext(TEXT_DOMAIN,
 			    "Would be able to return %s "
@@ -1245,13 +1245,14 @@ zpool_rewind_exclaim(libzfs_handle_t *hdl, const char *name, boolean_t dryrun,
 			(void) printf(dgettext(TEXT_DOMAIN,
 			    "%s approximately %lld "),
 			    dryrun ? "Would discard" : "Discarded",
-			    (loss + 30) / 60);
+			    ((longlong_t)loss + 30) / 60);
 			(void) printf(dgettext(TEXT_DOMAIN,
 			    "minutes of transactions.\n"));
 		} else if (loss > 0) {
 			(void) printf(dgettext(TEXT_DOMAIN,
 			    "%s approximately %lld "),
-			    dryrun ? "Would discard" : "Discarded", loss);
+			    dryrun ? "Would discard" : "Discarded",
+			    (longlong_t)loss);
 			(void) printf(dgettext(TEXT_DOMAIN,
 			    "seconds of transactions.\n"));
 		}
@@ -1289,7 +1290,7 @@ zpool_explain_recover(libzfs_handle_t *hdl, const char *name, int reason,
 	    "Recovery is possible, but will result in some data loss.\n"));
 
 	if (localtime_r((time_t *)&rewindto, &t) != NULL &&
-	    strftime(timestr, 128, 0, &t) != 0) {
+	    strftime(timestr, 128, "%c", &t) != 0) {
 		(void) printf(dgettext(TEXT_DOMAIN,
 		    "\tReturning the pool to its state as of %s\n"
 		    "\tshould correct the problem.  "),
@@ -1303,11 +1304,13 @@ zpool_explain_recover(libzfs_handle_t *hdl, const char *name, int reason,
 	if (loss > 120) {
 		(void) printf(dgettext(TEXT_DOMAIN,
 		    "Approximately %lld minutes of data\n"
-		    "\tmust be discarded, irreversibly.  "), (loss + 30) / 60);
+		    "\tmust be discarded, irreversibly.  "),
+		    ((longlong_t)loss + 30) / 60);
 	} else if (loss > 0) {
 		(void) printf(dgettext(TEXT_DOMAIN,
 		    "Approximately %lld seconds of data\n"
-		    "\tmust be discarded, irreversibly.  "), loss);
+		    "\tmust be discarded, irreversibly.  "),
+		    (longlong_t)loss);
 	}
 	if (edata != 0 && edata != UINT64_MAX) {
 		if (edata == 1) {
diff --git a/module/zfs/sa.c b/module/zfs/sa.c
index a91b379f99..17649274dd 100644
--- a/module/zfs/sa.c
+++ b/module/zfs/sa.c
@@ -1469,12 +1469,12 @@ sa_attr_register_sync(sa_handle_t *hdl, dmu_tx_t *tx)
 
 	mutex_enter(&sa->sa_lock);
 
-	if (!sa->sa_need_attr_registration || sa->sa_master_obj == NULL) {
+	if (!sa->sa_need_attr_registration || sa->sa_master_obj == 0) {
 		mutex_exit(&sa->sa_lock);
 		return;
 	}
 
-	if (sa->sa_reg_attr_obj == NULL) {
+	if (sa->sa_reg_attr_obj == 0) {
 		int error;
 		sa->sa_reg_attr_obj = zap_create(hdl->sa_os,
 		    DMU_OT_SA_ATTR_REGISTRATION, DMU_OT_NONE, 0, tx);
diff --git a/module/zfs/zfs_ioctl.c b/module/zfs/zfs_ioctl.c
index bba8956355..d1159c453e 100644
--- a/module/zfs/zfs_ioctl.c
+++ b/module/zfs/zfs_ioctl.c
@@ -2276,7 +2276,7 @@ zfs_ioc_set_prop(zfs_cmd_t *zc)
 
 	error = zfs_set_prop_nvlist(zc->zc_name, source, nvl, &errors);
 
-	if (zc->zc_nvlist_dst != NULL && errors != NULL) {
+	if (zc->zc_nvlist_dst != 0 && errors != NULL) {
 		(void) put_nvlist(zc, errors);
 	}
 
@@ -3711,7 +3711,7 @@ zfs_ioc_clear(zfs_cmd_t *zc)
 		nvlist_t *policy;
 		nvlist_t *config = NULL;
 
-		if (zc->zc_nvlist_src == NULL)
+		if (zc->zc_nvlist_src == 0)
 			return (EINVAL);
 
 		if ((error = get_nvlist(zc->zc_nvlist_src,