diff --git a/cmd/zfs/zfs_main.c b/cmd/zfs/zfs_main.c
index 76d98ad649..ea78254f2d 100644
--- a/cmd/zfs/zfs_main.c
+++ b/cmd/zfs/zfs_main.c
@@ -645,7 +645,7 @@ zfs_do_create(int argc, char **argv)
 		zfs_prop_t resv_prop;
 		char *strval;
 
-		if (p = strchr(argv[0], '/'))
+		if ((p = strchr(argv[0], '/')))
 			*p = '\0';
 		zpool_handle = zpool_open(g_zfs, argv[0]);
 		if (p != NULL)
diff --git a/cmd/zpool/zpool_iter.c b/cmd/zpool/zpool_iter.c
index bf947d307e..952d19172c 100644
--- a/cmd/zpool/zpool_iter.c
+++ b/cmd/zpool/zpool_iter.c
@@ -131,7 +131,7 @@ pool_list_get(int argc, char **argv, zprop_list_t **proplist, int *err)
 		for (i = 0; i < argc; i++) {
 			zpool_handle_t *zhp;
 
-			if (zhp = zpool_open_canfail(g_zfs, argv[i])) {
+			if ((zhp = zpool_open_canfail(g_zfs, argv[i]))) {
 				if (add_pool(zhp, zlp) != 0)
 					*err = B_TRUE;
 			} else {
diff --git a/config/Rules.am b/config/Rules.am
index 7ed117657e..175e4b6087 100644
--- a/config/Rules.am
+++ b/config/Rules.am
@@ -5,7 +5,7 @@ DEFAULT_INCLUDES = -I${top_srcdir}
 #
 # FIXME: Add -Wshadow once everything is working
 #
-AM_CFLAGS  = -Wall -Wstrict-prototypes -Werror -Wno-parentheses
+AM_CFLAGS  = -Wall -Wstrict-prototypes -Werror
 AM_CFLAGS += -Wno-switch -Wno-unused -Wno-missing-braces
 AM_CFLAGS += -Wno-uninitialized -fno-strict-aliasing
 
diff --git a/config/kernel.m4 b/config/kernel.m4
index 4a705b0e51..245bdc00de 100644
--- a/config/kernel.m4
+++ b/config/kernel.m4
@@ -10,7 +10,7 @@ AC_DEFUN([ZFS_AC_CONFIG_KERNEL], [
 	# FIXME: consider removing this as soon as we reasonably can
 	KERNELCPPFLAGS="$KERNELCPPFLAGS -Wall -Wstrict-prototypes -Werror"
 	KERNELCPPFLAGS="$KERNELCPPFLAGS -Wno-switch -Wno-unused"
-	KERNELCPPFLAGS="$KERNELCPPFLAGS -Wno-missing-braces -Wno-parentheses"
+	KERNELCPPFLAGS="$KERNELCPPFLAGS -Wno-missing-braces"
 	KERNELCPPFLAGS="$KERNELCPPFLAGS -Wno-uninitialized -fno-strict-aliasing"
 
 	KERNELCPPFLAGS="$KERNELCPPFLAGS -DHAVE_SPL -D_KERNEL "
diff --git a/lib/libzfs/libzfs_dataset.c b/lib/libzfs/libzfs_dataset.c
index 3bb1d8ca59..e4bb78f94b 100644
--- a/lib/libzfs/libzfs_dataset.c
+++ b/lib/libzfs/libzfs_dataset.c
@@ -636,7 +636,7 @@ libzfs_mnttab_fini(libzfs_handle_t *hdl)
 	void *cookie = NULL;
 	mnttab_node_t *mtn;
 
-	while (mtn = avl_destroy_nodes(&hdl->libzfs_mnttab_cache, &cookie)) {
+	while ((mtn = avl_destroy_nodes(&hdl->libzfs_mnttab_cache, &cookie))) {
 		free(mtn->mtn_mt.mnt_special);
 		free(mtn->mtn_mt.mnt_mountp);
 		free(mtn->mtn_mt.mnt_fstype);
@@ -688,7 +688,7 @@ libzfs_mnttab_remove(libzfs_handle_t *hdl, const char *fsname)
 	mnttab_node_t *ret;
 
 	find.mtn_mt.mnt_special = (char *)fsname;
-	if (ret = avl_find(&hdl->libzfs_mnttab_cache, (void *)&find, NULL)) {
+	if ((ret = avl_find(&hdl->libzfs_mnttab_cache, (void *)&find, NULL))) {
 		avl_remove(&hdl->libzfs_mnttab_cache, ret);
 		free(ret->mtn_mt.mnt_special);
 		free(ret->mtn_mt.mnt_mountp);
diff --git a/module/unicode/u8_textprep.c b/module/unicode/u8_textprep.c
index 34b0b9a8b9..2532769c86 100644
--- a/module/unicode/u8_textprep.c
+++ b/module/unicode/u8_textprep.c
@@ -144,9 +144,10 @@
 #define	U8_16BIT_TABLE_INDICATOR	(0x8000U)
 
 /* The following are some convenience macros. */
-#define	U8_PUT_3BYTES_INTO_UTF32(u, b1, b2, b3) \
-	(u) = ((uint32_t)(b1) & 0x0F) << 12 | ((uint32_t)(b2) & 0x3F) << 6 | \
-		(uint32_t)(b3) & 0x3F;
+#define	U8_PUT_3BYTES_INTO_UTF32(u, b1, b2, b3)  \
+	(u) = ((((uint32_t)(b1) & 0x0F) << 12) | \
+	       (((uint32_t)(b2) & 0x3F) << 6)  | \
+		((uint32_t)(b3) & 0x3F));
 
 #define	U8_SIMPLE_SWAP(a, b, t) \
 	(t) = (a); \
diff --git a/module/zfs/dnode.c b/module/zfs/dnode.c
index 2c320d4a37..7d82ca5c0f 100644
--- a/module/zfs/dnode.c
+++ b/module/zfs/dnode.c
@@ -1115,7 +1115,7 @@ dnode_free_range(dnode_t *dn, uint64_t off, uint64_t len, dmu_tx_t *tx)
 		int shift = epbs + dn->dn_datablkshift;
 
 		first = blkid >> epbs;
-		if (db = dbuf_hold_level(dn, 1, first, FTAG)) {
+		if ((db = dbuf_hold_level(dn, 1, first, FTAG))) {
 			dbuf_will_dirty(db, tx);
 			dbuf_rele(db, FTAG);
 		}
diff --git a/module/zfs/dnode_sync.c b/module/zfs/dnode_sync.c
index 4a8abaf672..02f533d6f8 100644
--- a/module/zfs/dnode_sync.c
+++ b/module/zfs/dnode_sync.c
@@ -591,7 +591,7 @@ dnode_sync(dnode_t *dn, dmu_tx_t *tx)
 	mutex_exit(&dn->dn_mtx);
 
 	/* process all the "freed" ranges in the file */
-	while (rp = avl_last(&dn->dn_ranges[txgoff])) {
+	while ((rp = avl_last(&dn->dn_ranges[txgoff]))) {
 		dnode_sync_free_range(dn, rp->fr_blkid, rp->fr_nblks, tx);
 		/* grab the mutex so we don't race with dnode_block_freed() */
 		mutex_enter(&dn->dn_mtx);
diff --git a/module/zfs/dsl_dataset.c b/module/zfs/dsl_dataset.c
index 4f943e2e36..cc7e08d9ec 100644
--- a/module/zfs/dsl_dataset.c
+++ b/module/zfs/dsl_dataset.c
@@ -2334,8 +2334,8 @@ dsl_dataset_promote_check(void *arg1, void *arg2, dmu_tx_t *tx)
 		if (ds->ds_phys->ds_prev_snap_obj == 0)
 			continue;
 
-		if (err = bplist_space(&ds->ds_deadlist,
-		    &dlused, &dlcomp, &dluncomp))
+		if ((err = bplist_space(&ds->ds_deadlist,
+		    &dlused, &dlcomp, &dluncomp)))
 			return (err);
 		pa->used += dlused;
 		pa->comp += dlcomp;
diff --git a/module/zfs/dsl_pool.c b/module/zfs/dsl_pool.c
index f4275ea067..44ccc90ee9 100644
--- a/module/zfs/dsl_pool.c
+++ b/module/zfs/dsl_pool.c
@@ -313,12 +313,12 @@ dsl_pool_sync(dsl_pool_t *dp, uint64_t txg)
 	ASSERT(err == 0);
 	DTRACE_PROBE(pool_sync__2rootzio);
 
-	while (dstg = txg_list_remove(&dp->dp_sync_tasks, txg))
+	while ((dstg = txg_list_remove(&dp->dp_sync_tasks, txg)))
 		dsl_sync_task_group_sync(dstg, tx);
 	DTRACE_PROBE(pool_sync__3task);
 
 	start = gethrtime();
-	while (dd = txg_list_remove(&dp->dp_dirty_dirs, txg))
+	while ((dd = txg_list_remove(&dp->dp_dirty_dirs, txg)))
 		dsl_dir_sync(dd, tx);
 	write_time += gethrtime() - start;
 
diff --git a/module/zfs/spa.c b/module/zfs/spa.c
index 57389a1338..1ec801130d 100644
--- a/module/zfs/spa.c
+++ b/module/zfs/spa.c
@@ -215,8 +215,8 @@ spa_prop_get(spa_t *spa, nvlist_t **nvp)
 
 				dp = spa_get_dsl(spa);
 				rw_enter(&dp->dp_config_rwlock, RW_READER);
-				if (err = dsl_dataset_hold_obj(dp,
-				    za.za_first_integer, FTAG, &ds)) {
+				if ((err = dsl_dataset_hold_obj(dp,
+				    za.za_first_integer, FTAG, &ds))) {
 					rw_exit(&dp->dp_config_rwlock);
 					break;
 				}
@@ -336,8 +336,8 @@ spa_prop_validate(spa_t *spa, nvlist_t *props)
 					break;
 				}
 
-				if (error = dmu_objset_open(strval, DMU_OST_ZFS,
-				    DS_MODE_USER | DS_MODE_READONLY, &os))
+				if ((error = dmu_objset_open(strval,DMU_OST_ZFS,
+				    DS_MODE_USER | DS_MODE_READONLY, &os)))
 					break;
 
 				/* We don't support gzip bootable datasets */
@@ -2369,7 +2369,7 @@ spa_check_rootconf(char *devpath, char *devid, nvlist_t **bestconf,
 	uint64_t txg;
 	int error;
 
-	if (error = vdev_disk_read_rootlabel(devpath, devid, &config))
+	if ((error = vdev_disk_read_rootlabel(devpath, devid, &config)))
 		return (error);
 
 	VERIFY(nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_TXG, &txg) == 0);
@@ -2415,7 +2415,7 @@ spa_get_rootconf(char *devpath, char *devid, nvlist_t **bestconf)
 
 	if (devpath && ((tmp = strchr(devpath, ' ')) != NULL))
 		*tmp = '\0';
-	if (error = spa_check_rootconf(devpath, devid, &conf, &txg)) {
+	if ((error = spa_check_rootconf(devpath, devid, &conf, &txg))) {
 		cmn_err(CE_NOTE, "error reading device label");
 		return (error);
 	}
@@ -2499,7 +2499,7 @@ spa_import_rootpool(char *devpath, char *devid)
 	 * Get the vdev pathname and configuation from the most
 	 * recently updated vdev (highest txg).
 	 */
-	if (error = spa_get_rootconf(devpath, devid, &conf))
+	if ((error = spa_get_rootconf(devpath, devid, &conf)))
 		goto msg_out;
 
 	/*
diff --git a/module/zfs/zfs_fuid.c b/module/zfs/zfs_fuid.c
index 286dafba80..ce2bc93030 100644
--- a/module/zfs/zfs_fuid.c
+++ b/module/zfs/zfs_fuid.c
@@ -161,12 +161,12 @@ zfs_fuid_table_destroy(avl_tree_t *idx_tree, avl_tree_t *domain_tree)
 	void *cookie;
 
 	cookie = NULL;
-	while (domnode = avl_destroy_nodes(domain_tree, &cookie))
+	while ((domnode = avl_destroy_nodes(domain_tree, &cookie)))
 		ksiddomain_rele(domnode->f_ksid);
 
 	avl_destroy(domain_tree);
 	cookie = NULL;
-	while (domnode = avl_destroy_nodes(idx_tree, &cookie))
+	while ((domnode = avl_destroy_nodes(idx_tree, &cookie)))
 		kmem_free(domnode, sizeof (fuid_domain_t));
 	avl_destroy(idx_tree);
 }
diff --git a/module/zfs/zfs_ioctl.c b/module/zfs/zfs_ioctl.c
index 7bb0fffa8e..f1e4207ab4 100644
--- a/module/zfs/zfs_ioctl.c
+++ b/module/zfs/zfs_ioctl.c
@@ -748,8 +748,8 @@ zfs_ioc_pool_create(zfs_cmd_t *zc)
 	nvlist_t *zplprops = NULL;
 	char *buf;
 
-	if (error = get_nvlist(zc->zc_nvlist_conf, zc->zc_nvlist_conf_size,
-	    &config))
+	if ((error = get_nvlist(zc->zc_nvlist_conf,
+				zc->zc_nvlist_conf_size, &config)))
 		return (error);
 
 	if (zc->zc_nvlist_src_size != 0 && (error =
@@ -1020,7 +1020,7 @@ zfs_ioc_dsobj_to_dsname(zfs_cmd_t *zc)
 {
 	int error;
 
-	if (error = dsl_dsobj_to_dsname(zc->zc_name, zc->zc_obj, zc->zc_value))
+	if ((error = dsl_dsobj_to_dsname(zc->zc_name,zc->zc_obj,zc->zc_value)))
 		return (error);
 
 	return (0);
@@ -1203,8 +1203,8 @@ zfs_ioc_objset_stats(zfs_cmd_t *zc)
 	int error;
 	nvlist_t *nv;
 
-	if (error = dmu_objset_open(zc->zc_name,
-	    DMU_OST_ANY, DS_MODE_USER | DS_MODE_READONLY, &os))
+	if ((error = dmu_objset_open(zc->zc_name,
+	    DMU_OST_ANY, DS_MODE_USER | DS_MODE_READONLY, &os)))
 		return (error);
 
 	dmu_objset_fast_stat(os, &zc->zc_objset_stats);
@@ -1261,8 +1261,8 @@ zfs_ioc_objset_zplprops(zfs_cmd_t *zc)
 	objset_t *os;
 	int err;
 
-	if (err = dmu_objset_open(zc->zc_name,
-	    DMU_OST_ANY, DS_MODE_USER | DS_MODE_READONLY, &os))
+	if ((err = dmu_objset_open(zc->zc_name,
+	    DMU_OST_ANY, DS_MODE_USER | DS_MODE_READONLY, &os)))
 		return (err);
 
 	dmu_objset_fast_stat(os, &zc->zc_objset_stats);
@@ -1310,8 +1310,8 @@ zfs_ioc_dataset_list_next(zfs_cmd_t *zc)
 	int error;
 	char *p;
 
-	if (error = dmu_objset_open(zc->zc_name,
-	    DMU_OST_ANY, DS_MODE_USER | DS_MODE_READONLY, &os)) {
+	if ((error = dmu_objset_open(zc->zc_name,
+	    DMU_OST_ANY, DS_MODE_USER | DS_MODE_READONLY, &os))) {
 		if (error == ENOENT)
 			error = ESRCH;
 		return (error);
@@ -1425,8 +1425,8 @@ zfs_set_prop_nvlist(const char *name, nvlist_t *nvl)
 			    nvpair_type(elem) != DATA_TYPE_STRING)
 				return (EINVAL);
 
-			if (error = zfs_secpolicy_write_perms(name,
-			    ZFS_DELEG_PERM_USERPROP, CRED()))
+			if ((error = zfs_secpolicy_write_perms(name,
+			    ZFS_DELEG_PERM_USERPROP, CRED())))
 				return (error);
 			continue;
 		}
diff --git a/module/zfs/zio.c b/module/zfs/zio.c
index b5f6cafe7d..2f0fef10bc 100644
--- a/module/zfs/zio.c
+++ b/module/zfs/zio.c
@@ -2204,11 +2204,12 @@ zio_done(zio_t *zio)
 		 */
 		ASSERT(vd == NULL && bp != NULL);
 
-		if (IO_IS_ALLOCATING(zio))
+		if (IO_IS_ALLOCATING(zio)) {
 			if (zio->io_error != ENOSPC)
 				zio->io_reexecute |= ZIO_REEXECUTE_NOW;
 			else
 				zio->io_reexecute |= ZIO_REEXECUTE_SUSPEND;
+		}
 
 		if ((zio->io_type == ZIO_TYPE_READ ||
 		    zio->io_type == ZIO_TYPE_FREE) &&