diff --git a/src/gio/memory_input_stream.rs b/src/gio/memory_input_stream.rs
index 46d8b6e..7149df4 100644
--- a/src/gio/memory_input_stream.rs
+++ b/src/gio/memory_input_stream.rs
@@ -25,7 +25,7 @@ use glib::{Bytes, Priority};
 /// * recursively read all bytes from `InputStream` for `SocketConnection` according to `bytes_in_chunk` argument
 /// * calculates total bytes length on every chunk iteration, validate sum with `bytes_total_limit` argument
 /// * stop reading `InputStream` with `Result` on zero bytes in chunk received
-/// * applies optional callback functions:
+/// * applies callback functions:
 ///   * `on_chunk` - return reference to [Bytes](https://docs.gtk.org/glib/struct.Bytes.html) and `bytes_total` collected for every chunk in reading loop
 ///   * `on_complete` - return `MemoryInputStream` on success or `Error` on failure as `Result`
 pub fn from_socket_connection_async(
@@ -34,8 +34,8 @@ pub fn from_socket_connection_async(
     priority: Priority,
     bytes_in_chunk: usize,
     bytes_total_limit: usize,
-    on_chunk: Option<impl Fn((&Bytes, &usize)) + 'static>,
-    on_complete: Option<impl FnOnce(Result<MemoryInputStream, (Error, Option<&str>)>) + 'static>,
+    on_chunk: impl Fn((&Bytes, &usize)) + 'static,
+    on_complete: impl FnOnce(Result<MemoryInputStream, (Error, Option<&str>)>) + 'static,
 ) {
     read_all_from_socket_connection_async(
         MemoryInputStream::new(),
@@ -56,7 +56,6 @@ pub fn from_socket_connection_async(
 /// Asynchronously read [InputStream](https://docs.gtk.org/gio/class.InputStream.html)
 /// from [SocketConnection](https://docs.gtk.org/gio/class.SocketConnection.html)
 /// to given [MemoryInputStream](https://docs.gtk.org/gio/class.MemoryInputStream.html).
-/// Applies optional `on_chunk` and `on_complete` callback functions.
 ///
 /// Useful to create dynamically allocated, memory-safe buffer
 /// from remote connections, where final size of target data could not be known by Gemini protocol restrictions.
@@ -71,7 +70,7 @@ pub fn from_socket_connection_async(
 /// * recursively read all bytes from `InputStream` for `SocketConnection` according to `bytes_in_chunk` argument
 /// * calculates total bytes length on every chunk iteration, validate sum with `bytes_total_limit` argument
 /// * stop reading `InputStream` with `Result` on zero bytes in chunk received, otherwise continue next chunk request in loop
-/// * applies optional callback functions:
+/// * applies callback functions:
 ///   * `on_chunk` - return reference to [Bytes](https://docs.gtk.org/glib/struct.Bytes.html) and `bytes_total` collected for every chunk in reading loop
 ///   * `on_complete` - return `MemoryInputStream` on success or `Error` on failure as `Result`
 pub fn read_all_from_socket_connection_async(
@@ -82,8 +81,8 @@ pub fn read_all_from_socket_connection_async(
     bytes_in_chunk: usize,
     bytes_total_limit: usize,
     bytes_total: usize,
-    on_chunk: Option<impl Fn((&Bytes, &usize)) + 'static>,
-    on_complete: Option<impl FnOnce(Result<MemoryInputStream, (Error, Option<&str>)>) + 'static>,
+    on_chunk: impl Fn((&Bytes, &usize)) + 'static,
+    on_complete: impl FnOnce(Result<MemoryInputStream, (Error, Option<&str>)>) + 'static,
 ) {
     socket_connection.input_stream().read_bytes_async(
         bytes_in_chunk,
@@ -95,24 +94,16 @@ pub fn read_all_from_socket_connection_async(
                 let bytes_total = bytes_total + bytes.len();
 
                 // Callback chunk function
-                if let Some(ref callback) = on_chunk {
-                    callback((&bytes, &bytes_total));
-                }
+                on_chunk((&bytes, &bytes_total));
 
                 // Validate max size
                 if bytes_total > bytes_total_limit {
-                    if let Some(callback) = on_complete {
-                        callback(Err((Error::BytesTotal, None)));
-                    }
-                    return; // break
+                    return on_complete(Err((Error::BytesTotal, None)));
                 }
 
                 // No bytes were read, end of stream
                 if bytes.len() == 0 {
-                    if let Some(callback) = on_complete {
-                        callback(Ok(memory_input_stream));
-                    }
-                    return; // break
+                    return on_complete(Ok(memory_input_stream));
                 }
 
                 // Write chunk bytes
@@ -132,9 +123,7 @@ pub fn read_all_from_socket_connection_async(
                 );
             }
             Err(reason) => {
-                if let Some(callback) = on_complete {
-                    callback(Err((Error::InputStream, Some(reason.message()))));
-                }
+                on_complete(Err((Error::InputStream, Some(reason.message()))));
             }
         },
     );