diff --git a/acvm_js/test/node/execute_circuit.test.ts b/acvm_js/test/node/execute_circuit.test.ts
index 3b84d8d9..dac93b9f 100644
--- a/acvm_js/test/node/execute_circuit.test.ts
+++ b/acvm_js/test/node/execute_circuit.test.ts
@@ -205,3 +205,29 @@ it("successfully executes two circuits with same backend", async function () {
   expect(solvedWitness0).to.be.deep.eq(expectedWitnessMap);
   expect(solvedWitness1).to.be.deep.eq(expectedWitnessMap);
 });
+
+it("successfully executes 500 circuits with same backend", async function () {
+  this.timeout(100000);
+
+  // chose pedersen op here because it is the one with slow initialization
+  // that led to the decision to pull backend initialization into a separate
+  // function/wasmbind
+  const solver: WasmBlackBoxFunctionSolver = await createBlackBoxSolver();
+
+  const { bytecode, initialWitnessMap, expectedWitnessMap } = await import(
+    "../shared/pedersen"
+  );
+
+  for (let i = 0; i < 500; i++) {
+    const solvedWitness = await executeCircuitWithBlackBoxSolver(
+      solver,
+      bytecode,
+      initialWitnessMap,
+      () => {
+        throw Error("unexpected oracle");
+      }
+    );
+
+    expect(solvedWitness).to.be.deep.eq(expectedWitnessMap);
+  }
+});
diff --git a/blackbox_solver/build.rs b/blackbox_solver/build.rs
index 3c911d9b..39db930b 100644
--- a/blackbox_solver/build.rs
+++ b/blackbox_solver/build.rs
@@ -7,7 +7,7 @@ use std::{
 const BARRETENBERG_ARCHIVE: &str = "BARRETENBERG_ARCHIVE";
 const BARRETENBERG_BIN_DIR: &str = "BARRETENBERG_BIN_DIR";
 
-const BARRETENBERG_ARCHIVE_FALLBACK: &str = "https://github.com/AztecProtocol/barretenberg/releases/download/barretenberg-v0.4.6/acvm_backend.wasm.tar.gz";
+const BARRETENBERG_ARCHIVE_FALLBACK: &str = "https://github.com/AztecProtocol/barretenberg/releases/download/barretenberg-v0.5.0/acvm_backend.wasm.tar.gz";
 // const ARCHIVE_SHA256: &str = "1xpycikqlvsjcryi3hkbc4mwmmdz7zshw6f76vyf1qssq53asyfx";
 
 fn unpack_wasm(archive_path: &Path, target_dir: &Path) -> Result<(), String> {
diff --git a/blackbox_solver/src/barretenberg/wasm/mod.rs b/blackbox_solver/src/barretenberg/wasm/mod.rs
index 78d77d99..995ef673 100644
--- a/blackbox_solver/src/barretenberg/wasm/mod.rs
+++ b/blackbox_solver/src/barretenberg/wasm/mod.rs
@@ -87,13 +87,23 @@ impl Barretenberg {
     #[cfg(not(target_arch = "wasm32"))]
     pub(crate) fn new() -> Barretenberg {
         let (instance, memory, store) = instance_load();
-        Barretenberg { memory, instance, store: RefCell::new(store) }
+        let barretenberg = Barretenberg { memory, instance, store: RefCell::new(store) };
+        barretenberg.call_wasi_initialize();
+        barretenberg
     }
 
     #[cfg(target_arch = "wasm32")]
     pub(crate) async fn initialize() -> Barretenberg {
         let (instance, memory, store) = instance_load().await;
-        Barretenberg { memory, instance, store: RefCell::new(store) }
+        let barretenberg = Barretenberg { memory, instance, store: RefCell::new(store) };
+        barretenberg.call_wasi_initialize();
+        barretenberg
+    }
+    /// Call initialization function for WASI, to initialize all of the appropriate
+    /// globals.
+    fn call_wasi_initialize(&self) {
+        self.call_multiple("_initialize", vec![])
+            .expect("expected call to WASI initialization function to not fail");
     }
 }