diff --git a/libconfig/src/lib.rs b/libconfig/src/lib.rs
index e1ca5f5..65e8312 100644
--- a/libconfig/src/lib.rs
+++ b/libconfig/src/lib.rs
@@ -56,9 +56,9 @@ impl<'a> From<FromUtf8Error> for Error<'a> {
     }
 }
 
-fn read_to_string<'a>(file: &mut File<'a>, read_str: &mut String) -> Result<'a, ()> {
-    let mut buffer = Vec::new();
-    let mut temp_buffer = [0; 500];
+// Simplified replacements to `read_to_end` and `read_to_string` from core_io
+fn read_to_end<'a>(file: &mut File<'a>, buffer: &mut Vec<u8>) -> Result<'a, ()> {
+    let mut temp_buffer = [0; 1024];
     loop {
         let read_bytes = file.read(&mut temp_buffer)?;
         if read_bytes != buffer.len() { 
@@ -69,18 +69,22 @@ fn read_to_string<'a>(file: &mut File<'a>, read_str: &mut String) -> Result<'a,
             buffer.extend_from_slice(&temp_buffer); 
         }
     }
-    read_str.extend(String::from_utf8(buffer));
     Ok(())
 }
 
+fn read_to_string<'a>(file: &mut File<'a>) -> Result<'a, String> {
+    let mut buffer: Vec<u8> = Vec::new();
+    read_to_end(file, &mut buffer);
+    Ok(String::from_utf8(buffer)?)
+}
+
 fn parse_config<'a>(
     key: &'a str,
     buffer: &mut Vec<u8>,
     mut file: File<'a>,
 ) -> Result<'a, ()> {
     let prefix = [key, "="].concat().to_ascii_lowercase();
-    let mut read_buffer = String::new();
-    read_to_string(&mut file, &mut read_buffer)?;
+    let read_buffer = read_to_string(&mut file)?;
     for line in read_buffer.lines() {
         let line = line.to_ascii_lowercase();
         if line.starts_with(&prefix) {
@@ -125,7 +129,7 @@ impl Config {
             let root_dir = fs.root_dir();
             let mut buffer: Vec<u8> = Vec::new();
             match root_dir.open_file(&["/CONFIG/", key, ".BIN"].concat()) {
-                Ok(mut f) => f.read(&mut buffer).map(|_| ())?,
+                Ok(mut f) => read_to_end( &mut f, &mut buffer)?,
                 Err(_) => match root_dir.open_file("/CONFIG.TXT") {
                     Ok(f) => parse_config(key, &mut buffer, f)?,
                     Err(_) => return Err(Error::KeyNotFoundError(key)),
@@ -150,8 +154,7 @@ impl Config {
                     let prefix = [key, "="].concat().to_ascii_lowercase();
                     match root_dir.create_file("/CONFIG.TXT") {
                         Ok(mut f) => {
-                            let mut buffer = String::new();
-                            read_to_string(&mut f, &mut buffer)?;
+                            let buffer = read_to_string(&mut f)?;
                             f.seek(SeekFrom::Start(0))?;
                             f.truncate()?;
                             for line in buffer.lines() {