diff --git a/Cargo.lock b/Cargo.lock
index 80373d4c1..5287f6b13 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -172,6 +172,15 @@ dependencies = [
  "bitflags 1.0.4 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "console_error_panic_hook"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cfg-if 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wasm-bindgen 0.2.29 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "constant_time_eq"
 version = "0.1.3"
@@ -723,6 +732,7 @@ name = "rustpython_wasm"
 version = "0.1.0"
 dependencies = [
  "cfg-if 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "console_error_panic_hook 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
  "js-sys 0.3.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustpython_parser 0.0.1",
  "rustpython_vm 0.1.0",
@@ -1151,6 +1161,7 @@ dependencies = [
 "checksum cfg-if 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "405216fd8fe65f718daa7102ea808a946b6ce40c742998fbfd3463645552de18"
 "checksum clap 2.31.2 (registry+https://github.com/rust-lang/crates.io-index)" = "f0f16b89cbb9ee36d87483dc939fe9f1e13c05898d56d7b230a0d4dff033a536"
 "checksum cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "ddfc5b9aa5d4507acaf872de71051dfd0e309860e88966e1051e462a077aac4f"
+"checksum console_error_panic_hook 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)" = "6c5dd2c094474ec60a6acaf31780af270275e3153bafff2db5995b715295762e"
 "checksum constant_time_eq 0.1.3 (registry+https://github.com/rust-lang/crates.io-index)" = "8ff012e225ce166d4422e0e78419d901719760f62ae2b7969ca6b564d1b54a9e"
 "checksum diff 0.1.11 (registry+https://github.com/rust-lang/crates.io-index)" = "3c2b69f912779fbb121ceb775d74d51e915af17aaebc38d28a592843a2dd0a3a"
 "checksum digest 0.7.2 (registry+https://github.com/rust-lang/crates.io-index)" = "00a49051fef47a72c9623101b19bd71924a45cca838826caae3eaa4d00772603"
diff --git a/wasm/lib/Cargo.toml b/wasm/lib/Cargo.toml
index bc2ee9d05..f7e2d1850 100644
--- a/wasm/lib/Cargo.toml
+++ b/wasm/lib/Cargo.toml
@@ -15,6 +15,7 @@ rustpython_vm = { path = "../../vm" }
 cfg-if = "0.1.2"
 wasm-bindgen = "0.2"
 js-sys = "0.3"
+console_error_panic_hook = "0.1"
 
 [dependencies.web-sys]
 version = "0.3"
diff --git a/wasm/lib/src/lib.rs b/wasm/lib/src/lib.rs
index 158345798..558cef102 100644
--- a/wasm/lib/src/lib.rs
+++ b/wasm/lib/src/lib.rs
@@ -15,6 +15,15 @@ use wasm_bindgen::prelude::*;
 
 pub use vm_class::*;
 
+#[cfg(debug_assertions)]
+extern crate console_error_panic_hook;
+
+#[cfg(debug_assertions)]
+#[wasm_bindgen(start)]
+pub fn setup_console_error() {
+    console_error_panic_hook::set_once();
+}
+
 // Hack to comment out wasm-bindgen's generated typescript definitons
 #[wasm_bindgen(typescript_custom_section)]
 const TS_CMT_START: &'static str = "/*";
diff --git a/wasm/lib/src/vm_class.rs b/wasm/lib/src/vm_class.rs
index 92998b145..b4a5a2646 100644
--- a/wasm/lib/src/vm_class.rs
+++ b/wasm/lib/src/vm_class.rs
@@ -1,6 +1,6 @@
 use convert;
 use js_sys::TypeError;
-use rustpython_vm::{pyobject::PyObjectRef, VirtualMachine};
+use rustpython_vm::{compile, pyobject::PyObjectRef, VirtualMachine};
 use std::cell::RefCell;
 use std::collections::HashMap;
 use wasm_bindgen::prelude::*;
@@ -50,9 +50,9 @@ impl VMStore {
         })
     }
 
-    pub fn destroy(id: &String) {
+    pub fn destroy(id: String) {
         STORED_VMS.with(|cell| {
-            cell.borrow_mut().remove(id);
+            cell.borrow_mut().remove(&id);
         });
     }
 
@@ -85,7 +85,7 @@ impl WASMVirtualMachine {
 
     pub fn destroy(&self) -> Result<(), JsValue> {
         self.assert_valid()?;
-        VMStore::destroy(&self.id);
+        VMStore::destroy(self.id.clone());
         Ok(())
     }
 
@@ -99,8 +99,26 @@ impl WASMVirtualMachine {
                 ref mut scope,
             } = vms.get_mut(&self.id).unwrap();
             let value = convert::js_to_py(vm, value);
-            vm.ctx.set_attr(scope, &name, value);
-        });
-        Ok(())
+            vm.ctx.set_item(scope, &name, value);
+            Ok(())
+        })
+    }
+
+    pub fn run(&self, mut source: String) -> Result<JsValue, JsValue> {
+        self.assert_valid()?;
+        STORED_VMS.with(|cell| {
+            let mut vms = cell.borrow_mut();
+            let StoredVirtualMachine {
+                ref mut vm,
+                ref mut scope,
+            } = vms.get_mut(&self.id).unwrap();
+            source.push('\n');
+            let code = compile::compile(vm, &source, compile::Mode::Single, None)
+                .map_err(|err| convert::py_str_err(vm, &err))?;
+            let result = vm
+                .run_code_obj(code, scope.clone())
+                .map_err(|err| convert::py_str_err(vm, &err))?;
+            Ok(convert::py_to_js(vm, result))
+        })
     }
 }