diff --git a/src/commands.rs b/src/commands.rs
index 182261e..ae46e5a 100644
--- a/src/commands.rs
+++ b/src/commands.rs
@@ -41,7 +41,7 @@ pub fn run(command: Command, flags: &oof::Flags) -> crate::Result<()> {
     match command {
         Command::Compress { files, output_path } => {
             // Formats from path extension, like "file.tar.gz.xz" -> vec![Tar, Gzip, Lzma]
-            let formats = extension::extensions_from_path(&output_path);
+            let mut formats = extension::extensions_from_path(&output_path);
 
             if formats.is_empty() {
                 let reason = FinalError::with_title(format!("Cannot compress to '{}'.", to_utf(&output_path)))
@@ -57,7 +57,7 @@ pub fn run(command: Command, flags: &oof::Flags) -> crate::Result<()> {
             }
 
             if matches!(&formats[0], Bzip | Gzip | Lzma) && represents_several_files(&files) {
-                // This piece of code creates a sugestion for compressing multiple files
+                // This piece of code creates a suggestion for compressing multiple files
                 // It says:
                 // Change from file.bz.xz
                 // To          file.tar.bz.xz
@@ -102,6 +102,22 @@ pub fn run(command: Command, flags: &oof::Flags) -> crate::Result<()> {
             }
 
             let output_file = fs::File::create(&output_path)?;
+
+            if files.len() == 1 {
+                // It's possible the file is already partially compressed so we don't want to compress it again
+                // `ouch compress file.tar.gz file.tar.gz.xz` should produce `file.tar.gz.xz` and not `file.tar.gz.tar.gz.xz`
+                let input_extensions = extension::extensions_from_path(&files[0]);
+
+                // If the input is a sublist at the start of `formats` then remove the extensions
+                // Note: If input_extensions is empty this counts as true
+                if !input_extensions.is_empty()
+                    && input_extensions.len() < formats.len()
+                    && input_extensions.iter().zip(&formats).all(|(inp, out)| inp == out)
+                {
+                    let drain_iter = formats.drain(..input_extensions.len());
+                    drop(drain_iter); // Remove the extensions from `formats`
+                }
+            }
             let compress_result = compress_files(files, formats, output_file, flags);
 
             // If any error occurred, delete incomplete file
@@ -163,24 +179,12 @@ pub fn run(command: Command, flags: &oof::Flags) -> crate::Result<()> {
 
 fn compress_files(
     files: Vec<PathBuf>,
-    mut formats: Vec<CompressionFormat>,
+    formats: Vec<CompressionFormat>,
     output_file: fs::File,
     _flags: &oof::Flags,
 ) -> crate::Result<()> {
     let file_writer = BufWriter::with_capacity(BUFFER_CAPACITY, output_file);
 
-    if files.len() == 1 {
-        // It's possible the file is already partially compressed so we don't want to compress it again
-        // `ouch compress file.tar.gz file.tar.gz.xz` should produce `file.tar.gz.xz` and not `file.tar.gz.tar.gz.xz`
-        let cur_extensions = extension::extensions_from_path(&files[0]);
-
-        // If the input is a subset at the start of `formats` then remove the extensions
-        if cur_extensions.len() < formats.len() && cur_extensions.iter().zip(&formats).all(|(inp, out)| inp == out) {
-            let drain_iter = formats.drain(..cur_extensions.len());
-            drop(drain_iter); // Remove the extensions from `formats`
-        }
-    }
-
     if let [Tar | Tgz | Zip] = *formats.as_slice() {
         match formats[0] {
             Tar => {