diff --git a/README.md b/README.md
index 5e21ea8..6eaf6f1 100644
--- a/README.md
+++ b/README.md
@@ -69,6 +69,7 @@ Options
  * -F or --allow-existing: Proceed (without deleting existing data) if the metadata or tiles table already exists
    or if metadata fields can't be set
  * -t _directory_ or --temporary-directory=_directory_: Put the temporary files in _directory_.
+   If you don't specify, it will use `/tmp`.
  * -P or --read-parallel: Use multiple threads to read different parts of each input file at once.
    This will only work if the input is line-delimited JSON with each Feature on its
    own line, because it knows nothing of the top-level structure around the Features. Spurious "EOF" error
diff --git a/man/tippecanoe.1 b/man/tippecanoe.1
index 75daad1..1fb86bd 100644
--- a/man/tippecanoe.1
+++ b/man/tippecanoe.1
@@ -77,6 +77,7 @@ specified, the files are all merged into the single named layer, even if they tr
 or if metadata fields can't be set
 .IP \(bu 2
 \-t \fIdirectory\fP or \-\-temporary\-directory=\fIdirectory\fP: Put the temporary files in \fIdirectory\fP\&.
+If you don't specify, it will use \fB\fC/tmp\fR\&.
 .IP \(bu 2
 \-P or \-\-read\-parallel: Use multiple threads to read different parts of each input file at once.
 This will only work if the input is line\-delimited JSON with each Feature on its