diff --git a/src/actions/build.rs b/src/actions/build.rs
index a2b3d51..eebc6a3 100644
--- a/src/actions/build.rs
+++ b/src/actions/build.rs
@@ -158,9 +158,12 @@ impl BuildAction<'_> {
     /// Prepare _wasm.rs file.
     fn build_wasm_sources(&self) {
         log::info("Generating _wasm.rs files...");
-        for contract in self.contracts() {
-            command::cargo_build_wasm_sources(self.builder_paths.root(), &contract.name);
-        }
+        let names = self
+            .contracts()
+            .iter()
+            .map(|c| c.name.to_owned())
+            .collect::<Vec<_>>();
+        command::cargo_build_wasm_sources(self.builder_paths.root(), &names);
     }
 
     /// Build _wasm.rs files into .wasm files.
diff --git a/src/command.rs b/src/command.rs
index 6ae5dd6..083231c 100644
--- a/src/command.rs
+++ b/src/command.rs
@@ -121,21 +121,18 @@ pub fn cargo_build_wasm_files(current_dir: PathBuf, contract_name: &str) {
 }
 
 /// Build wasm sources.
-pub fn cargo_build_wasm_sources(current_dir: PathBuf, contract_name: &str) {
-    cargo(
-        current_dir,
-        "run",
-        vec![
-            "--bin",
-            "contracts_build",
-            "--",
-            contract_name,
-            "--release",
-            "--no-default-features",
-            "--target-dir",
-            "../target",
-        ],
-    );
+pub fn cargo_build_wasm_sources(current_dir: PathBuf, contract_names: &[String]) {
+    let mut args = vec![
+        "--bin",
+        "contracts_build",
+        "--release",
+        "--no-default-features",
+        "--target-dir",
+        "../target",
+        "--",
+    ];
+    contract_names.iter().for_each(|name| args.push(name));
+    cargo(current_dir, "run", args);
 }
 
 /// Update a cargo module.