diff --git a/implementations/rust/preserves-tools/src/bin/preserves-tool.rs b/implementations/rust/preserves-tools/src/bin/preserves-tool.rs
index b11c32f..f70ae83 100644
--- a/implementations/rust/preserves-tools/src/bin/preserves-tool.rs
+++ b/implementations/rust/preserves-tools/src/bin/preserves-tool.rs
@@ -21,6 +21,8 @@ use preserves::value::Value;
 use preserves::value::ViaCodec;
 use preserves::value::Writer;
 
+use preserves::value::text::writer::CommaStyle;
+
 use std::iter::FromIterator;
 use std::io;
 use std::io::Read;
@@ -46,6 +48,13 @@ enum OutputFormat {
     Unquoted,
 }
 
+#[derive(ArgEnum, Clone, Debug)]
+enum CommasFormat {
+    None,
+    Separating,
+    Terminating,
+}
+
 #[derive(ArgEnum, Clone, Debug)]
 enum CompletionDialect {
     Bash,
@@ -69,6 +78,16 @@ impl From<Boolish> for bool {
     }
 }
 
+impl From<CommasFormat> for CommaStyle {
+    fn from(commas: CommasFormat) -> Self {
+        match commas {
+            CommasFormat::None => CommaStyle::None,
+            CommasFormat::Separating => CommaStyle::Separating,
+            CommasFormat::Terminating => CommaStyle::Terminating,
+        }
+    }
+}
+
 #[derive(ArgEnum, Clone, Debug)]
 enum SelectOutput {
     Sequence,
@@ -92,6 +111,9 @@ struct Convert {
     #[clap(long)]
     escape_spaces: bool,
 
+    #[clap(long, short, arg_enum, default_value = "none")]
+    commas: CommasFormat,
+
     #[clap(long)]
     limit: Option<usize>,
 
@@ -381,7 +403,9 @@ fn convert(c: Convert) -> io::Result<()> {
     let write_ann: bool = c.write_annotations.into();
     let mut w: Box<dyn FnMut(&IOValue) -> io::Result<()>> = match c.output_format {
         OutputFormat::Text => {
-            let mut t = TextWriter::new(io::stdout()).set_escape_spaces(c.escape_spaces);
+            let mut t = TextWriter::new(io::stdout())
+                .set_escape_spaces(c.escape_spaces)
+                .set_comma_style(c.commas.into());
             if c.indent.into() {
                 t.indentation = 2;
             }
diff --git a/implementations/rust/preserves/src/value/text/writer.rs b/implementations/rust/preserves/src/value/text/writer.rs
index 71acfc8..4643dca 100644
--- a/implementations/rust/preserves/src/value/text/writer.rs
+++ b/implementations/rust/preserves/src/value/text/writer.rs
@@ -12,7 +12,7 @@ use std::io;
 
 use super::super::boundary as B;
 
-#[derive(Clone, Copy)]
+#[derive(Clone, Copy, Debug)]
 pub enum CommaStyle {
     None,
     Separating,
@@ -59,6 +59,11 @@ impl<W: io::Write> TextWriter<W> {
         }
     }
 
+    pub fn set_comma_style(mut self, v: CommaStyle) -> Self {
+        self.comma_style = v;
+        self
+    }
+
     pub fn set_escape_spaces(mut self, v: bool) -> Self {
         self.escape_spaces = v;
         self