diff --git a/man/man5/zfs-module-parameters.5 b/man/man5/zfs-module-parameters.5
index 28c6e11d2f..e0000a23a1 100644
--- a/man/man5/zfs-module-parameters.5
+++ b/man/man5/zfs-module-parameters.5
@@ -822,9 +822,45 @@ Default value: \fB300\fR.
 \fBzfs_flags\fR (int)
 .ad
 .RS 12n
-Set additional debugging flags
+Set additional debugging flags. The following flags may be bitwise-or'd
+together.
 .sp
-Default value: \fB1\fR.
+.TS
+box;
+rB lB
+lB lB
+r l.
+Value	Symbolic Name
+	Description
+_
+1	ZFS_DEBUG_DPRINTF
+	Enable dprintf entries in the debug log.
+_
+2	ZFS_DEBUG_DBUF_VERIFY *
+	Enable extra dbuf verifications.
+_
+4	ZFS_DEBUG_DNODE_VERIFY *
+	Enable extra dnode verifications.
+_
+8	ZFS_DEBUG_SNAPNAMES
+	Enable snapshot name verification.
+_
+16	ZFS_DEBUG_MODIFY
+	Check for illegally modified ARC buffers.
+_
+32	ZFS_DEBUG_SPA
+	Enable spa_dbgmsg entries in the debug log.
+_
+64	ZFS_DEBUG_ZIO_FREE
+	Enable verification of block frees.
+_
+128	ZFS_DEBUG_HISTOGRAM_VERIFY
+	Enable extra spacemap histogram verifications.
+.TE
+.sp
+* Requires debug build.
+.sp
+Default value: \fB0\fR.
 .RE
 
 .sp
diff --git a/module/zfs/spa_misc.c b/module/zfs/spa_misc.c
index 2d16d7e06e..2a2e72d5a3 100644
--- a/module/zfs/spa_misc.c
+++ b/module/zfs/spa_misc.c
@@ -1980,7 +1980,7 @@ EXPORT_SYMBOL(spa_mode);
 
 EXPORT_SYMBOL(spa_namespace_lock);
 
-module_param(zfs_flags, int, 0644);
+module_param(zfs_flags, uint, 0644);
 MODULE_PARM_DESC(zfs_flags, "Set additional debugging flags");
 
 module_param(zfs_recover, int, 0644);