diff --git a/src/cmd/build.rs b/src/cmd/build.rs
index 4b45d91a380f8bbac5c42437ee2f928e57514f6e..32542d39f4501b4b0ac4fca3cbf5343b3557d649 100644
--- a/src/cmd/build.rs
+++ b/src/cmd/build.rs
@@ -317,9 +317,9 @@ fn do_optimization(
     let codegen_config = binaryen::CodegenConfig {
         // Number of optimization passes (spends potentially a lot of time optimizing)
         optimization_level: optimization_level.to_passes(),
-        // the default
+        // The default
         shrink_level: optimization_level.to_shrink(),
-        // the default
+        // The default
         debug_info: false,
     };
     let mut module = binaryen::Module::read(&dest_wasm_file_content)
@@ -478,7 +478,8 @@ pub(crate) fn execute_with_crate_metadata(
 #[cfg(test)]
 mod tests_ci_only {
     use crate::{
-        cmd, util::tests::with_tmp_dir, BuildArtifacts, ManifestPath, UnstableFlags, Verbosity,
+        cmd, util::tests::with_tmp_dir, BuildArtifacts, ManifestPath, OptimizationPasses,
+        UnstableFlags, Verbosity,
     };
 
     #[test]
@@ -487,14 +488,13 @@ mod tests_ci_only {
             cmd::new::execute("new_project", Some(path)).expect("new project creation failed");
             let manifest_path =
                 ManifestPath::new(&path.join("new_project").join("Cargo.toml")).unwrap();
-            let optimization_passes = 3;
             let res = super::execute(
                 &manifest_path,
                 Verbosity::Default,
                 true,
                 BuildArtifacts::All,
                 UnstableFlags::default(),
-                optimization_passes,
+                OptimizationPasses::default(),
             )
             .expect("build failed");
 
@@ -523,7 +523,6 @@ mod tests_ci_only {
             cmd::new::execute("new_project", Some(path)).expect("new project creation failed");
             let project_dir = path.join("new_project");
             let manifest_path = ManifestPath::new(&project_dir.join("Cargo.toml")).unwrap();
-            let optimization_passes = 3;
 
             // when
             super::execute(
@@ -532,7 +531,7 @@ mod tests_ci_only {
                 true,
                 BuildArtifacts::CheckOnly,
                 UnstableFlags::default(),
-                optimization_passes,
+                OptimizationPasses::default(),
             )
             .expect("build failed");
 
diff --git a/src/cmd/metadata.rs b/src/cmd/metadata.rs
index 0c2365f55b978edbd2cfb676758a0ed076cbec33..a1c2ea1a412666914d19e6084b5f08ba813d3d5b 100644
--- a/src/cmd/metadata.rs
+++ b/src/cmd/metadata.rs
@@ -287,7 +287,7 @@ mod tests {
     use crate::cmd::metadata::blake2_hash;
     use crate::{
         cmd, crate_metadata::CrateMetadata, util::tests::with_tmp_dir, BuildArtifacts,
-        ManifestPath, UnstableFlags, Verbosity,
+        ManifestPath, OptimizationPasses, UnstableFlags, Verbosity,
     };
     use contract_metadata::*;
     use serde_json::{Map, Value};
@@ -386,6 +386,7 @@ mod tests {
                 Verbosity::Default,
                 BuildArtifacts::All,
                 UnstableFlags::default(),
+                OptimizationPasses::default(),
             )?
             .dest_bundle
             .expect("bundle file not found");
diff --git a/src/main.rs b/src/main.rs
index 5347044e4cd18a3e30a26baa527150cd735c4a18..26369b448771c50424029657109f411e7721bf4b 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -95,7 +95,7 @@ impl ExtrinsicOpts {
 
 #[derive(Clone, Debug, StructOpt)]
 pub struct OptimizationFlags {
-    /// number of optimization passes, passed as an argument to wasm-opt
+    /// Number of optimization passes, passed as an argument to wasm-opt.
     ///
     /// - `0`: execute no optimization passes
     ///
@@ -128,6 +128,12 @@ pub enum OptimizationPasses {
     Z,
 }
 
+impl Default for OptimizationPasses {
+    fn default() -> OptimizationPasses {
+        OptimizationPasses::Three
+    }
+}
+
 impl TryFrom<&OptimizationFlags> for OptimizationPasses {
     type Error = Error;