diff --git a/cmds/filesystem-usage.c b/cmds/filesystem-usage.c
index 4c4467ee..52e552dc 100644
--- a/cmds/filesystem-usage.c
+++ b/cmds/filesystem-usage.c
@@ -478,6 +478,8 @@ static int print_filesystem_usage_overall(int fd, const struct array *chunkinfos
 	bool mixed = false;
 	struct statvfs statvfs_buf;
 	struct btrfs_ioctl_feature_flags feature_flags;
+	bool raid56 = false;
+	bool unreliable_allocated = false;
 
 	sargs = load_space_info(fd, path);
 	if (!sargs) {
@@ -518,8 +520,10 @@ static int print_filesystem_usage_overall(int fd, const struct array *chunkinfos
 		 * computed separately. Setting ratio to 0 will not account
 		 * the chunks in this loop.
 		 */
-		if (flags & BTRFS_BLOCK_GROUP_RAID56_MASK)
+		if (flags & BTRFS_BLOCK_GROUP_RAID56_MASK) {
 			ratio = 0;
+			raid56 = true;
+		}
 
 		if (ratio > max_data_ratio)
 			max_data_ratio = ratio;
@@ -610,6 +614,18 @@ static int print_filesystem_usage_overall(int fd, const struct array *chunkinfos
 		ret = 0;
 	}
 
+	/*
+	 * If we don't have any chunk information (e.g. due to missing
+	 * privileges) and there's a raid56 profile, the computation of
+	 * "unallocated", "data/metadata ratio", "free estimated" are wrong.
+	 */
+	unreliable_allocated = (raid56 && chunkinfos->length == 0);
+	if (unreliable_allocated) {
+		warning("radid56 found, we cannots compute some values, run as root if needed");
+		ret = 1;
+		goto exit;
+	}
+
 	pr_verbose(LOG_DEFAULT, "Overall:\n");
 
 	pr_verbose(LOG_DEFAULT, "    Device size:\t\t%*s\n", width,