diff --git a/src/main.rs b/src/main.rs
index ba59ad3..3df57db 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -2,6 +2,7 @@
 // SPDX-License-Identifier: EUPL-1.2
 
 mod settings;
+mod sizes;
 
 use {
     anyhow::Result,
@@ -143,7 +144,7 @@ async fn s3_fileview(path: &PathBuf, settings: &Settings) -> Result<Vec<FileView
                 path.map(|path| FileViewItem {
                     path: path.to_owned(),
                     size_bytes: obj.size,
-                    size: size_bytes_to_human(obj.size),
+                    size: sizes::bytes_to_human(obj.size),
                     last_modification: obj.last_modified.clone(),
                 })
             });
@@ -156,29 +157,6 @@ async fn s3_fileview(path: &PathBuf, settings: &Settings) -> Result<Vec<FileView
     Ok(objects)
 }
 
-fn size_bytes_to_human(bytes: u64) -> String {
-    use human_size::{Any, SpecificSize};
-
-    let size: f64 = bytes as f64;
-    let digits = size.log10().floor() as u32;
-    let mut order = digits / 3;
-    let unit = match order {
-        0 => Any::Byte,
-        1 => Any::Kilobyte,
-        2 => Any::Megabyte,
-        _ => {
-            order = 3; // Let's stop here.
-            Any::Gigabyte
-        }
-    };
-
-    format!(
-        "{:.3}",
-        SpecificSize::new(size / 10u64.pow(order * 3) as f64, unit)
-            .unwrap_or(SpecificSize::new(0., Any::Byte).unwrap())
-    )
-}
-
 lazy_static! {
     // Workaround for https://github.com/SergioBenitez/Rocket/issues/1792
     static ref EMPTY_DIR: tempfile::TempDir = tempfile::tempdir()
@@ -203,22 +181,3 @@ fn rocket() -> _ {
                 .unwrap()
         }))
 }
-
-// -------------------------------------------------------------
-
-#[cfg(test)]
-mod tests {
-    use rstest::rstest;
-
-    #[rstest]
-    #[case(1024, "1.024 kB")]
-    #[case(10240, "10.240 kB")]
-    #[case(1024*1024, "1.049 MB")]
-    #[case(1024*1024*1024, "1.074 GB")]
-    #[case(0, "0.000 B")]
-    #[case(u64::MAX, format!("{:.3} GB",u64::MAX as f64/(1_000_000_000.0)))]
-    #[case(u64::MIN, format!("{:.3} B",u64::MIN as f64))]
-    fn size_bytes_to_human(#[case] bytes: u64, #[case] expected: String) {
-        assert_eq!(super::size_bytes_to_human(bytes), expected);
-    }
-}
diff --git a/src/sizes.rs b/src/sizes.rs
new file mode 100644
index 0000000..8d80287
--- /dev/null
+++ b/src/sizes.rs
@@ -0,0 +1,44 @@
+// SPDX-FileCopyrightText: © Matteo Settenvini <matteo.settenvini@montecristosoftware.eu>
+// SPDX-License-Identifier: EUPL-1.2
+
+pub fn bytes_to_human(bytes: u64) -> String {
+    use human_size::{Any, SpecificSize};
+
+    let size: f64 = bytes as f64;
+    let digits = size.log10().floor() as u32;
+    let mut order = digits / 3;
+    let unit = match order {
+        0 => Any::Byte,
+        1 => Any::Kilobyte,
+        2 => Any::Megabyte,
+        _ => {
+            order = 3; // Let's stop here.
+            Any::Gigabyte
+        }
+    };
+
+    format!(
+        "{:.3}",
+        SpecificSize::new(size / 10u64.pow(order * 3) as f64, unit)
+            .unwrap_or(SpecificSize::new(0., Any::Byte).unwrap())
+    )
+}
+
+// -------------------------------------------------------------
+
+#[cfg(test)]
+mod tests {
+    use rstest::rstest;
+
+    #[rstest]
+    #[case(1024, "1.024 kB")]
+    #[case(10240, "10.240 kB")]
+    #[case(1024*1024, "1.049 MB")]
+    #[case(1024*1024*1024, "1.074 GB")]
+    #[case(0, "0.000 B")]
+    #[case(u64::MAX, format!("{:.3} GB",u64::MAX as f64/(1_000_000_000.0)))]
+    #[case(u64::MIN, format!("{:.3} B",u64::MIN as f64))]
+    fn bytes_to_human(#[case] bytes: u64, #[case] expected: String) {
+        assert_eq!(super::bytes_to_human(bytes), expected);
+    }
+}