diff --git a/README.md b/README.md
index 90705f2..50d1e10 100644
--- a/README.md
+++ b/README.md
@@ -41,7 +41,7 @@ $ cattleya -i input -e
 start obfuscating input...
 obfuscation done!
 
-$ readeld -h input
+$ readelf -h input
 ELF Header:
   Magic:   7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00 
   Class:                             ELF64
@@ -151,7 +151,7 @@ Hex dump of section '.comment':
 Encrypts the name of a specific function with AES 256bit using the given key:
 
 ```
-$ cargo run -- -i bin/test_64bit --encrypt --encrypt-f fac --encrypt-key foo -o bin/res_enc
+$ cattleya -i bin/test_64bit --encrypt --encrypt-f fac --encrypt-key foo -o bin/res_enc
 start obfuscating bin/test_64bit...
 obfuscation done!
 $ ./bin/res_enc
diff --git a/src/obfus.rs b/src/obfus.rs
index 9ca2e10..0145123 100644
--- a/src/obfus.rs
+++ b/src/obfus.rs
@@ -341,15 +341,14 @@ impl Obfuscator {
             .truncate(true)
             .open("/tmp/cattleya_encrypted_function_name")
             .map_err(crate::error::Error::CreateFile)?;
-        let mut writer = aesstream::AesWriter::new(tmp_file, encryptor).unwrap();
-        writer
+        aesstream::AesWriter::new(tmp_file, encryptor)
+            .map_err(crate::error::Error::OpenFile)?
             .write_all(function.as_bytes())
             .map_err(crate::error::Error::Io)?;
 
         let mut encrypted_function_name = Vec::new();
-        let mut tmp_file = std::fs::File::open("/tmp/cattleya_encrypted_function_name")
-            .map_err(crate::error::Error::OpenFile)?;
-        tmp_file
+        std::fs::File::open("/tmp/cattleya_encrypted_function_name")
+            .map_err(crate::error::Error::OpenFile)?
             .read_to_end(&mut encrypted_function_name)
             .map_err(crate::error::Error::Io)?;