diff --git a/exampledir/compress/test.log b/exampledir/decompress/test.log
similarity index 100%
rename from exampledir/compress/test.log
rename to exampledir/decompress/test.log
diff --git a/exampledir/compress/test.log.bz2 b/exampledir/decompress/test.log.bz2
similarity index 100%
rename from exampledir/compress/test.log.bz2
rename to exampledir/decompress/test.log.bz2
diff --git a/exampledir/compress/test.log.gz b/exampledir/decompress/test.log.gz
similarity index 100%
rename from exampledir/compress/test.log.gz
rename to exampledir/decompress/test.log.gz
diff --git a/exampledir/compress/test.log.xz b/exampledir/decompress/test.log.xz
similarity index 100%
rename from exampledir/compress/test.log.xz
rename to exampledir/decompress/test.log.xz
diff --git a/exampledir/compress/test.log.zst b/exampledir/decompress/test.log.zst
similarity index 100%
rename from exampledir/compress/test.log.zst
rename to exampledir/decompress/test.log.zst
diff --git a/exampledir/decompress/testlogbutwithoutextension b/exampledir/decompress/testlogbutwithoutextension
new file mode 100644
index 0000000..ed0a24c
Binary files /dev/null and b/exampledir/decompress/testlogbutwithoutextension differ
diff --git a/exampledir/exampledir.tar.gz b/exampledir/tar/exampledir.tar.gz
similarity index 100%
rename from exampledir/exampledir.tar.gz
rename to exampledir/tar/exampledir.tar.gz
diff --git a/exampledir/test.tar b/exampledir/tar/test.tar
similarity index 100%
rename from exampledir/test.tar
rename to exampledir/tar/test.tar
diff --git a/exampledir/test.tar.bz2 b/exampledir/tar/test.tar.bz2
similarity index 100%
rename from exampledir/test.tar.bz2
rename to exampledir/tar/test.tar.bz2
diff --git a/exampledir/tar/test.tar.zip b/exampledir/tar/test.tar.zip
new file mode 100644
index 0000000..d55c53e
Binary files /dev/null and b/exampledir/tar/test.tar.zip differ
diff --git a/src/adapters/decompress.rs b/src/adapters/decompress.rs
index 141f0da..d92c500 100644
--- a/src/adapters/decompress.rs
+++ b/src/adapters/decompress.rs
@@ -45,22 +45,33 @@ impl GetMetadata for DecompressAdapter {
     }
 }
 
-fn decompress_any<'a, R>(filename: &Path, inp: &'a mut R) -> Fallible<Box<dyn Read + 'a>>
+fn decompress_any<'a, R>(reason: &SlowMatcher, inp: &'a mut R) -> Fallible<Box<dyn Read + 'a>>
 where
     R: Read,
 {
-    let extension = filename.extension().map(|e| e.to_string_lossy().to_owned());
+    use FastMatcher::*;
+    use SlowMatcher::*;
+    let gz = |inp: &'a mut R| Box::new(flate2::read::MultiGzDecoder::new(inp));
+    let bz2 = |inp: &'a mut R| Box::new(bzip2::read::BzDecoder::new(inp));
+    let xz = |inp: &'a mut R| Box::new(xz2::read::XzDecoder::new_multi_decoder(inp));
+    let zst = |inp: &'a mut R| zstd::stream::read::Decoder::new(inp); // returns result
 
-    match extension {
-        Some(e) => Ok(match e.to_owned().as_ref() {
-            "tgz" | "gz" => Box::new(flate2::read::MultiGzDecoder::new(inp)),
-            "tbz" | "tbz2" | "bz2" => Box::new(bzip2::read::BzDecoder::new(inp)),
-            "xz" => Box::new(xz2::read::XzDecoder::new_multi_decoder(inp)),
-            "zst" => Box::new(zstd::stream::read::Decoder::new(inp)?),
+    Ok(match reason {
+        Fast(FileExtension(ext)) => match ext.as_ref() {
+            "tgz" | "gz" => gz(inp),
+            "tbz" | "tbz2" | "bz2" => bz2(inp),
+            "xz" => xz(inp),
+            "zst" => Box::new(zst(inp)?),
             ext => Err(format_err!("don't know how to decompress {}", ext))?,
-        }),
-        None => Err(format_err!("no extension")),
-    }
+        },
+        MimeType(mime) => match mime.as_ref() {
+            "application/gzip" => gz(inp),
+            "application/x-bzip" => bz2(inp),
+            "application/x-xz" => xz(inp),
+            "application/zstd" => Box::new(zst(inp)?),
+            mime => Err(format_err!("don't know how to decompress mime {}", mime))?,
+        },
+    })
 }
 fn get_inner_filename(filename: &Path) -> PathBuf {
     let extension = filename
@@ -90,7 +101,7 @@ impl FileAdapter for DecompressAdapter {
             ..
         } = ai;
 
-        let mut decompress = decompress_any(filepath_hint, &mut inp)?;
+        let mut decompress = decompress_any(detection_reason, &mut inp)?;
         let ai2: AdaptInfo = AdaptInfo {
             filepath_hint: &get_inner_filename(filepath_hint),
             is_real_file: false,
diff --git a/src/matching.rs b/src/matching.rs
index 22b84c7..a62de7e 100644
--- a/src/matching.rs
+++ b/src/matching.rs
@@ -59,10 +59,14 @@ pub fn adapter_matcher<T: AsRef<str>>(
 		use SlowMatcher::*;
 		for matcher in metadata.get_matchers(slow) {
 			match matcher.as_ref() {
-				f @ MimeType(re) => mime_regexes.push((re.clone(), adapter.clone(), f)),
-				f @ Fast(FastMatcher::FileExtension(re)) => {
-					fname_regexes.push((extension_to_regex(re), adapter.clone(), f))
+				MimeType(re) => {
+					mime_regexes.push((re.clone(), adapter.clone(), MimeType(re.clone())))
 				}
+				Fast(FastMatcher::FileExtension(re)) => fname_regexes.push((
+					extension_to_regex(re),
+					adapter.clone(),
+					Fast(FastMatcher::FileExtension(re.clone())),
+				)),
 			};
 		}
 	}
@@ -112,11 +116,11 @@ pub fn adapter_matcher<T: AsRef<str>>(
 			if fname_matches.is_empty() {
 				None
 			} else {
-				let (_, adapter, matcher) = fname_regexes[fname_matches[0]];
+				let (_, adapter, matcher) = &fname_regexes[fname_matches[0]];
 				Some((adapter.clone(), matcher.clone()))
 			}
 		} else {
-			let (_, adapter, matcher) = mime_regexes[mime_matches[0]];
+			let (_, adapter, matcher) = &mime_regexes[mime_matches[0]];
 			Some((adapter.clone(), matcher.clone()))
 		}
 	})
diff --git a/src/preproc.rs b/src/preproc.rs
index a29bd4c..70719f6 100644
--- a/src/preproc.rs
+++ b/src/preproc.rs
@@ -101,7 +101,7 @@ pub fn rga_preproc(ai: AdaptInfo) -> Result<(), Error> {
                                 archive_recursion_depth,
                                 config: PreprocConfig { cache: None, args },
                             },
-                            detection_reason,
+                            &detection_reason,
                         )?;
                         let compressed = compbuf
                             .into_inner()
@@ -134,7 +134,7 @@ pub fn rga_preproc(ai: AdaptInfo) -> Result<(), Error> {
                         archive_recursion_depth,
                         config: PreprocConfig { cache: None, args },
                     },
-                    detection_reason,
+                    &detection_reason,
                 )?;
                 Ok(())
             }