diff --git a/cmds/filesystem-usage.c b/cmds/filesystem-usage.c
index 015c401e..4c4467ee 100644
--- a/cmds/filesystem-usage.c
+++ b/cmds/filesystem-usage.c
@@ -1302,10 +1302,19 @@ void print_device_chunks(const struct device_info *devinfo,
 		allocated += size;
 
 	}
-	pr_verbose(LOG_DEFAULT, "   Unallocated: %*s%10s\n",
-		(int)(20 - strlen("Unallocated")), "",
-		pretty_size_mode(devinfo->size - allocated,
-			unit_mode | UNITS_NEGATIVE));
+
+	/*
+	 * If chunkinfos is empty, we cannot compute the unallocated size, so
+	 * don't print incorrect data.
+	 */
+	if (chunkinfos->length == 0)
+		pr_verbose(LOG_DEFAULT, "   Unallocated: %*s%10s\n",
+			   (int)(20 - strlen("Unallocated")), "", "N/A");
+	else
+		pr_verbose(LOG_DEFAULT, "   Unallocated: %*s%10s\n",
+			   (int)(20 - strlen("Unallocated")), "",
+			   pretty_size_mode(devinfo->size - allocated,
+					    unit_mode | UNITS_NEGATIVE));
 }
 
 void print_device_sizes(const struct device_info *devinfo, unsigned unit_mode)