diff --git a/src/cpu.rs b/src/cpu.rs
index a13286c..6366104 100644
--- a/src/cpu.rs
+++ b/src/cpu.rs
@@ -29,8 +29,8 @@ impl CPU<u8> for ExampleCPU {
             registers: [0; 4],
         };
 
-        let len = initial_state.len();
-        let ram_len = instance.ram.len();
+        let len: usize = initial_state.len();
+        let ram_len: usize = instance.ram.len();
 
         if len >= ram_len {
             instance.ram.copy_from_slice(&initial_state[..ram_len]);
diff --git a/src/file.rs b/src/file.rs
index 33d7168..68a8759 100644
--- a/src/file.rs
+++ b/src/file.rs
@@ -17,8 +17,8 @@ pub fn save_binary_u8(file_path: &str, content: Vec<u8>) {
 }
 
 pub fn load_binary_u8(file_path: &str) -> Vec<u8> {
-    let mut file = File::open(file_path).unwrap();
-    let mut buffer = Vec::new();
+    let mut file: File = File::open(file_path).unwrap();
+    let mut buffer: Vec<u8> = Vec::new();
     file.read_to_end(&mut buffer).unwrap();
     buffer
 }