diff --git a/Chapter01/intro_expressions.rs b/Chapter01/intro_expressions.rs
index 446ccf7..e1422d5 100644
--- a/Chapter01/intro_expressions.rs
+++ b/Chapter01/intro_expressions.rs
@@ -38,14 +38,14 @@ fn main() {
 
     (1, 1.0, "".to_string());
 
-    let t = Term::TermVar {
+    let mut t = Term::TermVar {
         symbol: "".to_string()
     };
     match t {
        Term::TermVal { value: v1 } => v1,
        Term::TermVar { symbol: v1 } => v1,
-       Term::TermApp { f: v1, x: v2 } => "TermApp(?,?)".to_string(),
-       Term::TermAbs { arg: v1, body: v2 } => "TermAbs(?,?)".to_string()
+       Term::TermApp { f: ref v1, x: ref v2 } => "TermApp(?,?)".to_string(),
+       Term::TermAbs { arg: ref mut v1, body: ref mut v2 } => "TermAbs(?,?)".to_string()
     };
 
 }
diff --git a/Chapter01/intro_iterators.rs b/Chapter01/intro_iterators.rs
index 9548bb2..5ac13f2 100644
--- a/Chapter01/intro_iterators.rs
+++ b/Chapter01/intro_iterators.rs
@@ -16,6 +16,6 @@ fn main() {
 
     for i in (0..10) {}
 
-    let v: Vec<u32> = (0..10).collect();
+    (0..10).collect::<Vec<u64>>();
 
 }