diff --git a/exercises/variables/variables1.rs b/exercises/variables/variables1.rs
index 1cdd2702..708e8523 100644
--- a/exercises/variables/variables1.rs
+++ b/exercises/variables/variables1.rs
@@ -2,7 +2,7 @@
 // Make me compile! Scroll down for hints :)
 
 fn main() {
-    x = 5;
+    let x = 5;
     println!("x has the value {}", x);
 }
 
diff --git a/exercises/variables/variables2.rs b/exercises/variables/variables2.rs
index a0b4a376..0999b65c 100644
--- a/exercises/variables/variables2.rs
+++ b/exercises/variables/variables2.rs
@@ -2,7 +2,7 @@
 // Make me compile! Scroll down for hints :)
 
 fn main() {
-    let x;
+    let x: u32 = 9;
     if x == 10 {
         println!("Ten!");
     } else {
diff --git a/exercises/variables/variables3.rs b/exercises/variables/variables3.rs
index 165a2779..9076615f 100644
--- a/exercises/variables/variables3.rs
+++ b/exercises/variables/variables3.rs
@@ -2,7 +2,7 @@
 // Make me compile! Scroll down for hints :)
 
 fn main() {
-    let x = 3;
+    let mut x = 3;
     println!("Number {}", x);
     x = 5;
     println!("Number {}", x);
diff --git a/exercises/variables/variables4.rs b/exercises/variables/variables4.rs
index 71ebf0f0..cde9bf74 100644
--- a/exercises/variables/variables4.rs
+++ b/exercises/variables/variables4.rs
@@ -2,7 +2,7 @@
 // Make me compile! Scroll down for hints :)
 
 fn main() {
-    let x: i32;
+    let x: i32 = 69;
     println!("Number {}", x);
 }