diff --git a/ast/src/ast.rs b/ast/src/ast.rs
index f1fde50a9e..8506abf29d 100644
--- a/ast/src/ast.rs
+++ b/ast/src/ast.rs
@@ -159,7 +159,8 @@ impl<'ast> FromPest<'ast> for Expression<'ast> {
     type Rule = Rule;
 
     fn from_pest(pest: &mut Pairs<'ast, Rule>) -> Result<Self, ConversionError<Void>> {
-        let pair = pest.peek().ok_or(::from_pest::ConversionError::NoMatch)?;
+        let mut clone = pest.clone();
+        let pair = clone.next().ok_or(::from_pest::ConversionError::NoMatch)?;
         match pair.as_rule() {
             Rule::expression => {
                 // Transfer iterated state to pest.
diff --git a/compiler/src/expression/array/access.rs b/compiler/src/expression/array/access.rs
index a192477390..f1a388d3c2 100644
--- a/compiler/src/expression/array/access.rs
+++ b/compiler/src/expression/array/access.rs
@@ -42,7 +42,7 @@ impl<F: Field + PrimeField, G: GroupType<F>> ConstrainedProgram<F, G> {
             function_scope.clone(),
             expected_type,
             array,
-            span.clone(),
+            span,
         )? {
             ConstrainedValue::Array(array) => array,
             value => return Err(ExpressionError::undefined_array(value.to_string(), span.to_owned())),
diff --git a/compiler/src/expression/expression.rs b/compiler/src/expression/expression.rs
index 1209b6715a..5298c3eb50 100644
--- a/compiler/src/expression/expression.rs
+++ b/compiler/src/expression/expression.rs
@@ -75,7 +75,7 @@ impl<F: Field + PrimeField, G: GroupType<F>> ConstrainedProgram<F, G> {
                     expected_type,
                     left_right.0,
                     left_right.1,
-                    span.clone(),
+                    &span,
                 )?;
 
                 enforce_add(cs, resolved_left, resolved_right, &span)
@@ -88,7 +88,7 @@ impl<F: Field + PrimeField, G: GroupType<F>> ConstrainedProgram<F, G> {
                     expected_type,
                     left_right.0,
                     left_right.1,
-                    span.clone(),
+                    &span,
                 )?;
 
                 enforce_sub(cs, resolved_left, resolved_right, &span)
@@ -101,7 +101,7 @@ impl<F: Field + PrimeField, G: GroupType<F>> ConstrainedProgram<F, G> {
                     expected_type,
                     left_right.0,
                     left_right.1,
-                    span.clone(),
+                    &span,
                 )?;
 
                 enforce_mul(cs, resolved_left, resolved_right, &span)
@@ -114,7 +114,7 @@ impl<F: Field + PrimeField, G: GroupType<F>> ConstrainedProgram<F, G> {
                     expected_type,
                     left_right.0,
                     left_right.1,
-                    span.clone(),
+                    &span,
                 )?;
 
                 enforce_div(cs, resolved_left, resolved_right, &span)
@@ -127,7 +127,7 @@ impl<F: Field + PrimeField, G: GroupType<F>> ConstrainedProgram<F, G> {
                     expected_type,
                     left_right.0,
                     left_right.1,
-                    span.clone(),
+                    &span,
                 )?;
 
                 enforce_pow(cs, resolved_left, resolved_right, &span)
@@ -146,7 +146,7 @@ impl<F: Field + PrimeField, G: GroupType<F>> ConstrainedProgram<F, G> {
                     expected_type,
                     left_right.0,
                     left_right.1,
-                    span.clone(),
+                    &span,
                 )?;
 
                 Ok(enforce_or(cs, resolved_left, resolved_right, &span)?)
@@ -159,7 +159,7 @@ impl<F: Field + PrimeField, G: GroupType<F>> ConstrainedProgram<F, G> {
                     expected_type,
                     left_right.0,
                     left_right.1,
-                    span.clone(),
+                    &span,
                 )?;
 
                 Ok(enforce_and(cs, resolved_left, resolved_right, &span)?)
@@ -172,7 +172,7 @@ impl<F: Field + PrimeField, G: GroupType<F>> ConstrainedProgram<F, G> {
                     None,
                     left_right.0,
                     left_right.1,
-                    span.clone(),
+                    &span,
                 )?;
 
                 Ok(evaluate_eq(cs, resolved_left, resolved_right, &span)?)
@@ -185,7 +185,7 @@ impl<F: Field + PrimeField, G: GroupType<F>> ConstrainedProgram<F, G> {
                     None,
                     left_right.0,
                     left_right.1,
-                    span.clone(),
+                    &span,
                 )?;
 
                 Ok(evaluate_ge(cs, resolved_left, resolved_right, &span)?)
@@ -198,7 +198,7 @@ impl<F: Field + PrimeField, G: GroupType<F>> ConstrainedProgram<F, G> {
                     None,
                     left_right.0,
                     left_right.1,
-                    span.clone(),
+                    &span,
                 )?;
 
                 Ok(evaluate_gt(cs, resolved_left, resolved_right, &span)?)
@@ -211,7 +211,7 @@ impl<F: Field + PrimeField, G: GroupType<F>> ConstrainedProgram<F, G> {
                     None,
                     left_right.0,
                     left_right.1,
-                    span.clone(),
+                    &span,
                 )?;
 
                 Ok(evaluate_le(cs, resolved_left, resolved_right, &span)?)
@@ -224,7 +224,7 @@ impl<F: Field + PrimeField, G: GroupType<F>> ConstrainedProgram<F, G> {
                     None,
                     left_right.0,
                     left_right.1,
-                    span.clone(),
+                    &span,
                 )?;
 
                 Ok(evaluate_lt(cs, resolved_left, resolved_right, &span)?)
@@ -239,7 +239,7 @@ impl<F: Field + PrimeField, G: GroupType<F>> ConstrainedProgram<F, G> {
                 triplet.0,
                 triplet.1,
                 triplet.2,
-                span,
+                &span,
             ),
 
             // Arrays
@@ -253,7 +253,7 @@ impl<F: Field + PrimeField, G: GroupType<F>> ConstrainedProgram<F, G> {
                 expected_type,
                 array_w_index.0,
                 array_w_index.1,
-                span,
+                &span,
             ),
 
             // Tuples
diff --git a/compiler/src/statement/assign/assign.rs b/compiler/src/statement/assign/assign.rs
index f79f149ef5..0536775975 100644
--- a/compiler/src/statement/assign/assign.rs
+++ b/compiler/src/statement/assign/assign.rs
@@ -77,7 +77,7 @@ impl<F: Field + PrimeField, G: GroupType<F>> ConstrainedProgram<F, G> {
                 file_scope,
                 function_scope,
                 indicator,
-                variable_name,
+                &variable_name,
                 assignee_w_range_or_expression.1,
                 new_value,
                 span,
diff --git a/compiler/src/statement/assign/assignee.rs b/compiler/src/statement/assign/assignee.rs
index 895aa74191..13ba48f445 100644
--- a/compiler/src/statement/assign/assignee.rs
+++ b/compiler/src/statement/assign/assignee.rs
@@ -23,7 +23,7 @@ use snarkos_models::curves::{Field, PrimeField};
 
 pub fn resolve_assignee(scope: &str, assignee: Assignee) -> String {
     match assignee {
-        Assignee::Identifier(name) => new_scope(scope, name.to_string()),
+        Assignee::Identifier(name) => new_scope(scope, &name.to_string()),
         Assignee::Array(array_w_index) => resolve_assignee(scope, array_w_index.0),
         Assignee::Tuple(tuple, _index) => resolve_assignee(scope, *tuple),
         Assignee::CircuitField(circuit_name, _member) => resolve_assignee(scope, *circuit_name),