diff --git a/CHANGELOG.md b/CHANGELOG.md
index 4bb61a82..2ab180c7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@ Subheadings to categorize changes are `added, changed, deprecated, removed, fixe
 ## Unreleased
 ### fixed
 - Fixed [#148](https://github.com/thedodd/trunk/issues/148): any changes detected under a `.git` path are now being ignored by default.
+- Fixed [#163](https://github.com/thedodd/trunk/issues/163): allow using `copy-file` assets with files without a file extension.
 
 ## 0.10.0
 ### changed
diff --git a/src/pipelines/inline.rs b/src/pipelines/inline.rs
index a432512d..cc6dbb4b 100644
--- a/src/pipelines/inline.rs
+++ b/src/pipelines/inline.rs
@@ -33,7 +33,7 @@ impl Inline {
         path.extend(href_attr.split('/'));
 
         let asset = AssetFile::new(&html_dir, path).await?;
-        let content_type = ContentType::from_attr_or_ext(attrs.get(ATTR_TYPE), &asset.ext)?;
+        let content_type = ContentType::from_attr_or_ext(attrs.get(ATTR_TYPE), asset.ext.as_deref())?;
 
         Ok(Self { id, asset, content_type })
     }
@@ -72,10 +72,15 @@ pub enum ContentType {
 impl ContentType {
     /// Either tries to parse the provided attribute to a ContentType
     /// or tries to infer the ContentType from the AssetFile extension.
-    fn from_attr_or_ext(attr: Option<impl AsRef<str>>, ext: &str) -> Result<Self> {
+    fn from_attr_or_ext(attr: Option<impl AsRef<str>>, ext: Option<&str>) -> Result<Self> {
         match attr {
             Some(attr) => Self::from_str(attr.as_ref()),
-            None => Self::from_str(ext),
+            None => match ext {
+                Some(ext) => Self::from_str(ext),
+                None => bail!(
+                    r#"unknown type value for <link data-trunk rel="inline" .../> attr; please ensure the value is lowercase and is a supported content type"#,
+                ),
+            },
         }
     }
 }
diff --git a/src/pipelines/mod.rs b/src/pipelines/mod.rs
index 504b17ce..9d0f9a83 100644
--- a/src/pipelines/mod.rs
+++ b/src/pipelines/mod.rs
@@ -134,7 +134,7 @@ pub struct AssetFile {
     /// The file stem of the asset file.
     pub file_stem: OsString,
     /// The extension of the file.
-    pub ext: String,
+    pub ext: Option<String>,
 }
 
 impl AssetFile {
@@ -168,8 +168,8 @@ impl AssetFile {
             None => bail!("asset has no file name stem {:?}", &path),
         };
         let ext = match path.extension() {
-            Some(ext) => ext.to_string_lossy().to_lowercase(),
-            None => bail!("asset has no file extension {:?}", &path),
+            Some(ext) => Some(ext.to_owned().to_string_lossy().to_string()),
+            None => None,
         };
         Ok(Self {
             path: path.into(),
@@ -199,7 +199,12 @@ impl AssetFile {
             .await
             .with_context(|| format!("error reading file for copying {:?}", &self.path))?;
         let hash = seahash::hash(bytes.as_ref());
-        let file_name = format!("{}-{:x}.{}", &self.file_stem.to_string_lossy(), hash, &self.ext);
+        let file_name = format!(
+            "{}-{:x}.{}",
+            &self.file_stem.to_string_lossy(),
+            hash,
+            &self.ext.as_deref().unwrap_or_default()
+        );
 
         let file_path = to_dir.join(&file_name);
         fs::write(&file_path, bytes)