diff --git a/lib/emscripten/src/lib.rs b/lib/emscripten/src/lib.rs
index b834f8d03..1da2e6aba 100644
--- a/lib/emscripten/src/lib.rs
+++ b/lib/emscripten/src/lib.rs
@@ -163,7 +163,7 @@ fn copy_string_into_wasm(instance: &mut Instance, string: String) -> CallResult<
     }
     .unwrap();
 
-    let raw_memory = instance.inner.vmctx.memory(0)[space_offset as usize] as *mut u8;
+    let raw_memory = instance.ctx().memory(0)[space_offset as usize] as *mut u8;
 
     let slice = unsafe { slice::from_raw_parts_mut(raw_memory, string_len) };
 
@@ -194,7 +194,7 @@ fn create_wasm_array(instance: &mut Instance, values: Vec<u32>) -> CallResult<u3
     }
     .unwrap();
 
-    let raw_memory = instance.inner.vmctx.memory(0)[values_offset as usize] as *mut u32;
+    let raw_memory = instance.ctx().memory(0)[values_offset as usize] as *mut u32;
 
     let slice = unsafe { slice::from_raw_parts_mut(raw_memory, values_len) };
 
@@ -213,7 +213,7 @@ fn create_wasm_array(instance: &mut Instance, values: Vec<u32>) -> CallResult<u3
     }
     .unwrap();
 
-    let raw_memory = instance.inner.vmctx.memory(0)[values_offset as usize] as *mut u32;
+    let raw_memory = instance.ctx().memory(0)[values_offset as usize] as *mut u32;
 
     unsafe { *raw_memory = values_offset };
 
diff --git a/lib/runtime-core/src/instance.rs b/lib/runtime-core/src/instance.rs
index c48aa89e8..a37926799 100644
--- a/lib/runtime-core/src/instance.rs
+++ b/lib/runtime-core/src/instance.rs
@@ -25,8 +25,8 @@ pub struct InstanceInner {
 
 /// A WebAssembly instance
 pub struct Instance {
-    pub module: Rc<ModuleInner>,
-    pub inner: Box<InstanceInner>,
+    module: Rc<ModuleInner>,
+    inner: Box<InstanceInner>,
     #[allow(dead_code)]
     imports: Box<ImportObject>,
 }
@@ -100,6 +100,10 @@ impl Instance {
     pub fn module(&self) -> Module {
         Module::new(Rc::clone(&self.module))
     }
+
+    pub fn ctx(&mut self) -> &mut vm::Ctx {
+        &mut self.inner.vmctx
+    }
 }
 
 impl Instance {