diff --git a/cmds-fi-usage.c b/cmds-fi-usage.c
index 8764fef6..88e346ad 100644
--- a/cmds-fi-usage.c
+++ b/cmds-fi-usage.c
@@ -471,7 +471,7 @@ static int print_filesystem_usage_overall(int fd, struct chunk_info *chunkinfo,
 	printf("    Device allocated:\t\t%*s\n", width,
 		pretty_size_mode(r_total_chunks, unit_mode));
 	printf("    Device unallocated:\t\t%*s\n", width,
-		pretty_size_mode(r_total_unused, unit_mode));
+		pretty_size_mode(r_total_unused, unit_mode | UNITS_NEGATIVE));
 	printf("    Device missing:\t\t%*s\n", width,
 		pretty_size_mode(r_total_missing, unit_mode));
 	printf("    Used:\t\t\t%*s\n", width,
@@ -736,8 +736,8 @@ static void _cmd_filesystem_usage_tabular(unsigned unit_mode,
 		unused = get_partition_size(device_info_ptr[i].path)
 				- total_allocated;
 
-		table_printf(matrix, unallocated_col, vhdr_skip + i,
-			       ">%s", pretty_size_mode(unused, unit_mode));
+		table_printf(matrix, unallocated_col, vhdr_skip + i, ">%s",
+			pretty_size_mode(unused, unit_mode | UNITS_NEGATIVE));
 		total_unused += unused;
 
 	}
@@ -771,7 +771,8 @@ static void _cmd_filesystem_usage_tabular(unsigned unit_mode,
 	}
 
 	table_printf(matrix, unallocated_col, vhdr_skip + device_info_count + 1,
-			">%s", pretty_size_mode(total_unused, unit_mode));
+		">%s",
+		pretty_size_mode(total_unused, unit_mode | UNITS_NEGATIVE));
 
 	table_printf(matrix, 1, vhdr_skip + device_info_count + 2, "<Used");
 	for (i = 0, col = spaceinfos_col; i < sargs->total_spaces; i++) {
@@ -884,7 +885,7 @@ static void _cmd_filesystem_usage_linear(unsigned unit_mode,
 
 	printf("Unallocated:\n");
 	print_unused(info_ptr, info_count, device_info_ptr, device_info_count,
-			unit_mode);
+			unit_mode | UNITS_NEGATIVE);
 }
 
 static int print_filesystem_usage_by_chunk(int fd,
@@ -1027,7 +1028,8 @@ void print_device_chunks(int fd, struct device_info *devinfo,
 	}
 	printf("   Unallocated: %*s%10s\n",
 		(int)(20 - strlen("Unallocated")), "",
-		pretty_size_mode(devinfo->size - allocated, unit_mode));
+		pretty_size_mode(devinfo->size - allocated,
+			unit_mode | UNITS_NEGATIVE));
 }
 
 void print_device_sizes(int fd, struct device_info *devinfo, unsigned unit_mode)