diff --git a/zokrates_analysis/src/boolean_array_comparator.rs b/zokrates_analysis/src/boolean_array_comparator.rs
index 72c15819..e549917b 100644
--- a/zokrates_analysis/src/boolean_array_comparator.rs
+++ b/zokrates_analysis/src/boolean_array_comparator.rs
@@ -22,7 +22,7 @@ pub struct BooleanArrayComparator;
 
 impl BooleanArrayComparator {
     pub fn simplify<T: Field>(p: TypedProgram<T>) -> TypedProgram<T> {
-        Self::default().fold_program(p)
+        Self.fold_program(p)
     }
 }
 
@@ -141,7 +141,7 @@ mod tests {
             ]),
         ));
 
-        let res = BooleanArrayComparator::default().fold_boolean_expression(e);
+        let res = BooleanArrayComparator.fold_boolean_expression(e);
 
         assert_eq!(res, expected);
     }
@@ -171,7 +171,7 @@ mod tests {
             ]),
         ));
 
-        let res = BooleanArrayComparator::default().fold_boolean_expression(e);
+        let res = BooleanArrayComparator.fold_boolean_expression(e);
 
         assert_eq!(res, expected);
     }
diff --git a/zokrates_analysis/src/log_ignorer.rs b/zokrates_analysis/src/log_ignorer.rs
index 2c8aa5a8..06bd520c 100644
--- a/zokrates_analysis/src/log_ignorer.rs
+++ b/zokrates_analysis/src/log_ignorer.rs
@@ -6,7 +6,7 @@ pub struct LogIgnorer;
 
 impl LogIgnorer {
     pub fn ignore<T: Field>(p: TypedProgram<T>) -> TypedProgram<T> {
-        Self::default().fold_program(p)
+        Self.fold_program(p)
     }
 }
 
diff --git a/zokrates_analysis/src/out_of_bounds.rs b/zokrates_analysis/src/out_of_bounds.rs
index 7ed8613a..e00cf179 100644
--- a/zokrates_analysis/src/out_of_bounds.rs
+++ b/zokrates_analysis/src/out_of_bounds.rs
@@ -18,7 +18,7 @@ impl fmt::Display for Error {
 }
 impl OutOfBoundsChecker {
     pub fn check<T: Field>(p: TypedProgram<T>) -> Result<TypedProgram<T>, Error> {
-        Self::default().fold_program(p)
+        Self.fold_program(p)
     }
 }
 
diff --git a/zokrates_ast/src/ir/clean.rs b/zokrates_ast/src/ir/clean.rs
index 1c58faff..ac1bcbd0 100644
--- a/zokrates_ast/src/ir/clean.rs
+++ b/zokrates_ast/src/ir/clean.rs
@@ -16,7 +16,7 @@ impl<'ast, T: Field, I: IntoIterator<Item = Statement<'ast, T>>> ProgIterator<'a
             statements: self
                 .statements
                 .into_iter()
-                .flat_map(|s| Cleaner::default().fold_statement(s)),
+                .flat_map(|s| Cleaner.fold_statement(s)),
             solvers: self.solvers,
         }
     }
diff --git a/zokrates_core/src/optimizer/mod.rs b/zokrates_core/src/optimizer/mod.rs
index 08a6c1b7..6cd3628e 100644
--- a/zokrates_core/src/optimizer/mod.rs
+++ b/zokrates_core/src/optimizer/mod.rs
@@ -27,9 +27,9 @@ pub fn optimize<'ast, T: Field, I: IntoIterator<Item = Statement<'ast, T>>>(
 
     // define all optimizer steps
     let mut redefinition_optimizer = RedefinitionOptimizer::init(&p);
-    let mut tautologies_optimizer = TautologyOptimizer::default();
+    let mut tautologies_optimizer = TautologyOptimizer;
     let mut directive_optimizer = DirectiveOptimizer::default();
-    let mut canonicalizer = Canonicalizer::default();
+    let mut canonicalizer = Canonicalizer;
     let mut duplicate_optimizer = DuplicateOptimizer::default();
 
     use zokrates_ast::ir::folder::Folder;