diff --git a/src/runtime/backing.rs b/src/runtime/backing.rs
index f6ffb8220..a5348c256 100644
--- a/src/runtime/backing.rs
+++ b/src/runtime/backing.rs
@@ -24,13 +24,17 @@ impl LocalBacking {
         let mut tables = Self::generate_tables(module);
         let globals = Self::generate_globals(module);
 
+        let vm_memories = Self::finalize_memories(module, &mut memories[..]);
+        let vm_tables = Self::finalize_tables(module, &mut tables[..]);
+        let vm_globals = Self::finalize_globals(module, imports, globals);
+
         Self {
             memories,
             tables,
 
-            vm_memories: Self::finalize_memories(module, &mut memories[..]),
-            vm_tables: Self::finalize_tables(module, &mut tables[..]),
-            vm_globals: Self::finalize_globals(module, imports, globals),
+            vm_memories,
+            vm_tables,
+            vm_globals,
         }
     }
 
@@ -60,15 +64,16 @@ impl LocalBacking {
 
     fn finalize_memories(module: &Module, memories: &mut [LinearMemory]) -> Box<[vm::LocalMemory]> {
         for init in &module.data_initializers {
-            debug_assert!(init.base.is_none(), "globalvar base not supported yet");
+            assert!(init.base.is_none(), "globalvar base not supported yet");
+            assert!(init.offset + init.data.len() <= memories[init.memory_index.index()].current_size());
             let offset = init.offset;
             let mem: &mut LinearMemory = &mut memories[init.memory_index.index()];
             let end_of_init = offset + init.data.len();
-            if end_of_init > mem.current_size() {
-                let grow_pages = (end_of_init / LinearMemory::PAGE_SIZE as usize) + 1;
-                mem.grow(grow_pages as u32)
-                    .expect("failed to grow memory for data initializers");
-            }
+            // if end_of_init > mem.current_size() {
+            //     let grow_pages = (end_of_init / LinearMemory::PAGE_SIZE as usize) + 1;
+            //     mem.grow(grow_pages as u32)
+            //         .expect("failed to grow memory for data initializers");
+            // }
             let to_init = &mut mem[offset..offset + init.data.len()];
             to_init.copy_from_slice(&init.data);
         }
@@ -87,24 +92,26 @@ impl LocalBacking {
         tables.into_boxed_slice()
     }
 
-    fn finalize_tables(module: &Module, tables: &[TableBacking]) -> Box<[vm::LocalTable]> {
-        tables.iter().map(|table| table.into_vm_table()).collect::<Vec<_>>().into_boxed_slice()
+    // TODO: Actually finish this
+    fn finalize_tables(module: &Module, tables: &mut [TableBacking]) -> Box<[vm::LocalTable]> {
+        tables.iter_mut().map(|table| table.into_vm_table()).collect::<Vec<_>>().into_boxed_slice()
     }
 
+    // TODO: Actually finish this
     fn generate_globals(module: &Module) -> Box<[vm::LocalGlobal]> {
         let mut globals = vec![vm::LocalGlobal::null(); module.globals.len()];
 
         globals.into_boxed_slice()
     }
 
-    fn finalize_globals(module: &Module, imports: &ImportBacking, globals: Box<[vm::LocalGlobal]>) -> Box<[vm::LocalGlobal]> {
+    fn finalize_globals(module: &Module, imports: &ImportBacking, mut globals: Box<[vm::LocalGlobal]>) -> Box<[vm::LocalGlobal]> {
         for (to, (_, from)) in globals.iter_mut().zip(module.globals.into_iter()) {
             to.data = match from.init {
                 GlobalInit::Val(Val::I32(x)) => x as u64,
                 GlobalInit::Val(Val::I64(x)) => x as u64,
                 GlobalInit::Val(Val::F32(x)) => x as u64,
                 GlobalInit::Val(Val::F64(x)) => x,
-                GlobalInit::GetGlobal(index) => unsafe { (imports.globals[index.index()].global).data },
+                GlobalInit::GetGlobal(index) => (imports.globals[index.index()].global).data,
             };
         }
 
@@ -195,10 +202,10 @@ impl ImportBacking {
         let mut functions = Vec::with_capacity(module.imported_functions.len());
         for (index, (mod_name, item_name)) in &module.imported_functions {
             let expected_sig_index = module.signature_assoc[index];
-            let expected_sig = module.signatures[expected_sig_index];
+            let expected_sig = &module.signatures[expected_sig_index];
             let import = imports.get(mod_name, item_name);
             if let Some(Import::Func(func, signature)) = import {
-                if &expected_sig == signature {
+                if expected_sig == signature {
                     functions.push(vm::ImportedFunc {
                         func: *func,
                         // vmctx: ptr::null_mut(),
diff --git a/src/runtime/sig_registry.rs b/src/runtime/sig_registry.rs
index 949d2547e..f862f555c 100644
--- a/src/runtime/sig_registry.rs
+++ b/src/runtime/sig_registry.rs
@@ -22,11 +22,11 @@ impl SigRegistry {
         self.signatures.as_ptr()
     }
 
-    pub fn register(&mut self, signature: FuncSig, sig_index: SigIndex) {
+    pub fn register(&mut self, signature: FuncSig) {
         let index = self.sig_set.len();
-        let vm_sig_id = *self.sig_set.entry(signature).or_insert_with(|| {
+        let vm_sig_id = self.sig_set.entry(signature).or_insert_with(|| {
             vm::SigId(index as u32)
         });
-        self.signatures.push(vm_sig_id);
+        self.signatures.push(*vm_sig_id);
     }
 }
\ No newline at end of file
diff --git a/src/runtime/table.rs b/src/runtime/table.rs
index 10c237a6b..7bbe872d1 100644
--- a/src/runtime/table.rs
+++ b/src/runtime/table.rs
@@ -2,7 +2,7 @@ use super::vm;
 use crate::runtime::types::{ElementType, Table};
 
 #[derive(Debug, Clone)]
-enum TableElements {
+pub enum TableElements {
     /// This is intended to be a caller-checked Anyfunc.
     Anyfunc(Box<[vm::Anyfunc]>),
 }
@@ -27,7 +27,7 @@ impl TableBacking {
 
     pub fn into_vm_table(&mut self) -> vm::LocalTable {
         match self.elements {
-            TableElements::Anyfunc(funcs) => {
+            TableElements::Anyfunc(ref mut funcs) => {
                 vm::LocalTable {
                     base: funcs.as_mut_ptr() as *mut u8,
                     current_elements: funcs.len(),
diff --git a/src/runtime/vm.rs b/src/runtime/vm.rs
index b622768c2..832ba1edb 100644
--- a/src/runtime/vm.rs
+++ b/src/runtime/vm.rs
@@ -210,7 +210,7 @@ impl ImportedGlobal {
     }
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug, Clone, Copy)]
 #[repr(transparent)]
 pub struct SigId(pub u32);