diff --git a/exercises/02_functions/functions1.rs b/exercises/02_functions/functions1.rs
index a812c21..7639836 100644
--- a/exercises/02_functions/functions1.rs
+++ b/exercises/02_functions/functions1.rs
@@ -3,3 +3,5 @@
 fn main() {
     call_me(); // Don't change this line
 }
+
+fn call_me() {}
diff --git a/exercises/02_functions/functions2.rs b/exercises/02_functions/functions2.rs
index 2c773c6..a2cffc1 100644
--- a/exercises/02_functions/functions2.rs
+++ b/exercises/02_functions/functions2.rs
@@ -1,5 +1,5 @@
 // TODO: Add the missing type of the argument `num` after the colon `:`.
-fn call_me(num:) {
+fn call_me(num: i32) {
     for i in 0..num {
         println!("Ring! Call number {}", i + 1);
     }
diff --git a/exercises/02_functions/functions3.rs b/exercises/02_functions/functions3.rs
index 8d65477..845a1b4 100644
--- a/exercises/02_functions/functions3.rs
+++ b/exercises/02_functions/functions3.rs
@@ -6,5 +6,5 @@ fn call_me(num: u8) {
 
 fn main() {
     // TODO: Fix the function call.
-    call_me();
+    call_me(4);
 }
diff --git a/exercises/02_functions/functions4.rs b/exercises/02_functions/functions4.rs
index b22bffd..c1e078c 100644
--- a/exercises/02_functions/functions4.rs
+++ b/exercises/02_functions/functions4.rs
@@ -8,7 +8,7 @@ fn is_even(num: i64) -> bool {
 }
 
 // TODO: Fix the function signature.
-fn sale_price(price: i64) -> {
+fn sale_price(price: i64) -> i64 {
     if is_even(price) {
         price - 10
     } else {
diff --git a/exercises/02_functions/functions5.rs b/exercises/02_functions/functions5.rs
index 34a2ac7..a063100 100644
--- a/exercises/02_functions/functions5.rs
+++ b/exercises/02_functions/functions5.rs
@@ -1,6 +1,6 @@
 // TODO: Fix the function body without changing the signature.
 fn square(num: i32) -> i32 {
-    num * num;
+    num * num
 }
 
 fn main() {