diff --git a/Cargo.lock b/Cargo.lock
index 3d651c0be..6239f550d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -458,7 +458,7 @@ dependencies = [
  "log",
  "smallvec",
  "thiserror",
- "wasmparser 0.73.1",
+ "wasmparser 0.75.0",
 ]
 
 [[package]]
@@ -2678,15 +2678,15 @@ checksum = "a950e6a618f62147fd514ff445b2a0b53120d382751960797f85f058c7eda9b9"
 
 [[package]]
 name = "wasmparser"
-version = "0.73.1"
+version = "0.75.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b8526ab131cbc49495a483c98954913ae7b83551adacab5e294cf77992e70ee7"
+checksum = "4580b6be7329cfc3277131fc8363044990effb57b3ce93ef304ca70ad4339c64"
 
 [[package]]
 name = "wast"
-version = "22.0.0"
+version = "33.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fe1220ed7f824992b426a76125a3403d048eaf0f627918e97ade0d9b9d510d20"
+checksum = "1d04fe175c7f78214971293e7d8875673804e736092206a3a4544dbc12811c1b"
 dependencies = [
  "leb128",
 ]
@@ -2795,7 +2795,7 @@ dependencies = [
 
 [[package]]
 name = "witx"
-version = "0.8.8"
+version = "0.9.0"
 dependencies = [
  "anyhow",
  "log",
diff --git a/lucet-wiggle/generate/Cargo.toml b/lucet-wiggle/generate/Cargo.toml
index ec768fbf4..fa67c0532 100644
--- a/lucet-wiggle/generate/Cargo.toml
+++ b/lucet-wiggle/generate/Cargo.toml
@@ -11,7 +11,7 @@ edition = "2018"
 [dependencies]
 wiggle-generate = { path = "../../wasmtime/crates/wiggle/generate", version = "0.23.0" }
 lucet-module = { path = "../../lucet-module", version = "0.7.0-dev" }
-witx = { path = "../../wasmtime/crates/wasi-common/WASI/tools/witx", version = "0.8.4" }
+witx = { path = "../../wasmtime/crates/wasi-common/WASI/tools/witx", version = "0.9" }
 quote = "1.0"
 proc-macro2 = "1.0"
 heck = "*"
diff --git a/lucet-wiggle/generate/src/lib.rs b/lucet-wiggle/generate/src/lib.rs
index 0ba655b78..d518d946c 100644
--- a/lucet-wiggle/generate/src/lib.rs
+++ b/lucet-wiggle/generate/src/lib.rs
@@ -3,7 +3,7 @@ pub use config::Config;
 
 use heck::SnakeCase;
 use lucet_module::bindings::Bindings;
-use proc_macro2::{Ident, TokenStream};
+use proc_macro2::{Ident, Span, TokenStream};
 use quote::{format_ident, quote};
 
 pub fn hostcall_name(m: &witx::Module, f: &witx::InterfaceFunc) -> String {
@@ -40,34 +40,34 @@ pub fn generate(
     let fs = doc.modules().map(|m| {
         let fs = m.funcs().map(|f| {
             let name = format_ident!("{}", hostcall_name(&m, &f));
-            let coretype = f.core_type();
-            let func_args = coretype.args.iter().map(|a| {
-                let name = names.func_core_arg(a);
-                let atom = names.atom_type(a.repr());
+            let (params, results) = f.wasm_signature();
+            let arg_names = (0..params.len())
+                .map(|i| Ident::new(&format!("arg{}", i), Span::call_site()))
+                .collect::<Vec<_>>();
+            let func_args = params.iter().enumerate().map(|(i, ty)| {
+                let name = &arg_names[i];
+                let atom = names.wasm_type(*ty);
                 quote!(#name: #atom)
             });
-            let call_args = coretype.args.iter().map(|a| {
-                let name = names.func_core_arg(a);
-                quote!(#name)
-            });
-            let rets = coretype
-                .ret
-                .as_ref()
-                .map(|r| {
-                    let atom = names.atom_type(r.repr());
-                    quote!(#atom)
-                })
-                .unwrap_or(quote!(()));
+            let ret_ty = match results.len() {
+                0 => quote!(()),
+                1 => names.wasm_type(results[0]),
+                _ => panic!(
+                    "lucet-wiggle only supports 0 or 1 result type. function {} has: {:?}",
+                    hostcall_name(&m, &f),
+                    results
+                ),
+            };
             let mod_name = names.module(&m.name);
             let method_name = names.func(&f.name);
             quote! {
                 #[lucet_hostcall]
                 #[no_mangle]
-                pub fn #name(vmctx: &lucet_runtime::vmctx::Vmctx, #(#func_args),*) -> #rets {
+                pub fn #name(vmctx: &lucet_runtime::vmctx::Vmctx, #(#func_args),*) -> #ret_ty {
                     { #pre_hook }
                     let memory = lucet_wiggle::runtime::LucetMemory::new(vmctx);
                     let mut ctx: #ctx_type = #ctx_constructor;
-                    let r = super::#mod_name::#method_name(&ctx, &memory, #(#call_args),*);
+                    let r = super::#mod_name::#method_name(&ctx, &memory, #(#arg_names),*);
                     { #post_hook }
                     match r {
                         Ok(r) => { r },
diff --git a/lucet-wiggle/macro/Cargo.toml b/lucet-wiggle/macro/Cargo.toml
index 10a6c2292..71bcd70de 100644
--- a/lucet-wiggle/macro/Cargo.toml
+++ b/lucet-wiggle/macro/Cargo.toml
@@ -14,6 +14,6 @@ proc-macro = true
 [dependencies]
 lucet-wiggle-generate = { path = "../generate", version = "0.7.0-dev" }
 wiggle-generate = { path = "../../wasmtime/crates/wiggle/generate", version = "0.23.0" }
-witx = { path = "../../wasmtime/crates/wasi-common/WASI/tools/witx", version = "0.8.8" }
+witx = { path = "../../wasmtime/crates/wasi-common/WASI/tools/witx", version = "0.9" }
 syn = { version = "1.0", features = ["full"] }
 quote = "1.0"
diff --git a/lucetc/Cargo.toml b/lucetc/Cargo.toml
index 6522f6610..84b5f6ae1 100644
--- a/lucetc/Cargo.toml
+++ b/lucetc/Cargo.toml
@@ -26,7 +26,7 @@ cranelift-wasm = { path = "../wasmtime/cranelift/wasm", version = "0.70.0" }
 target-lexicon = "0.11"
 lucet-module = { path = "../lucet-module", version = "=0.7.0-dev" }
 lucet-wiggle-generate = { path = "../lucet-wiggle/generate", version = "=0.7.0-dev" }
-witx = { path = "../wasmtime/crates/wasi-common/WASI/tools/witx", version = "0.8.5" }
+witx = { path = "../wasmtime/crates/wasi-common/WASI/tools/witx", version = "0.9" }
 wasmparser = "0.59.0"
 clap="2.32"
 
diff --git a/lucetc/src/validate.rs b/lucetc/src/validate.rs
index 52cd2dd9f..ba0c3bc2d 100644
--- a/lucetc/src/validate.rs
+++ b/lucetc/src/validate.rs
@@ -4,7 +4,7 @@ use thiserror::Error;
 use witx::Id;
 
 pub use cranelift_wasm::{WasmFuncType, WasmType};
-pub use witx::{AtomType, Document, WitxError};
+pub use witx::{Document, WitxError};
 
 #[derive(Debug, Error, Clone, PartialEq, Eq)]
 pub enum Error {
@@ -187,7 +187,7 @@ impl Validator {
                 .ok_or(not_found.clone())?
                 .func(&Id::new(field))
                 .ok_or(not_found)?;
-            let spec_type = witx_to_functype(&func.core_type());
+            let spec_type = witx_to_functype(&func);
             if &spec_type != type_ {
                 Err(Error::ImportTypeError {
                     module: module.to_owned(),
@@ -235,25 +235,25 @@ impl Validator {
     }
 }
 
-fn witx_to_functype(coretype: &witx::CoreFuncType) -> WasmFuncType {
-    fn atom_to_type(atom: &witx::AtomType) -> WasmType {
+fn witx_to_functype(func: &witx::InterfaceFunc) -> WasmFuncType {
+    fn atom_to_type(atom: &witx::WasmType) -> WasmType {
         match atom {
-            witx::AtomType::I32 => WasmType::I32,
-            witx::AtomType::I64 => WasmType::I64,
-            witx::AtomType::F32 => WasmType::F32,
-            witx::AtomType::F64 => WasmType::F64,
+            witx::WasmType::I32 => WasmType::I32,
+            witx::WasmType::I64 => WasmType::I64,
+            witx::WasmType::F32 => WasmType::F32,
+            witx::WasmType::F64 => WasmType::F64,
         }
     }
-    let params = coretype
-        .args
+    let (params, results) = func.wasm_signature();
+    let params = params
         .iter()
-        .map(|a| atom_to_type(&a.repr()))
+        .map(|a| atom_to_type(&a))
         .collect::<Vec<_>>()
         .into_boxed_slice();
-    let returns = if let Some(ref r) = coretype.ret {
-        vec![atom_to_type(&r.repr())].into_boxed_slice()
-    } else {
-        vec![].into_boxed_slice()
+    let returns = match results.len() {
+        0 => vec![].into_boxed_slice(),
+        1 => vec![atom_to_type(&results[0])].into_boxed_slice(),
+        _ => unimplemented!("multiple result types"),
     };
     WasmFuncType { params, returns }
 }
diff --git a/lucetc/tests/wasm.rs b/lucetc/tests/wasm.rs
index d9806719d..b60fc64d1 100644
--- a/lucetc/tests/wasm.rs
+++ b/lucetc/tests/wasm.rs
@@ -640,7 +640,7 @@ mod validate {
         let b = stub_wasi_bindings();
 
         let witx = "
-(typename $errno (enum u8 $inval))
+(typename $errno (enum (@witx tag u8) $inval))
 (module $wasi_snapshot_preview1
   (import \"memory\" (memory))
   ;;; Read command-line argument data.
@@ -648,7 +648,7 @@ mod validate {
   (@interface func (export \"args_get\")
     (param $argv (@witx pointer (@witx pointer u8)))
     (param $argv_buf (@witx pointer u8))
-    (result $error $errno)
+    (result $error (expected (error $errno)))
   )
 )";
         let v = Validator::builder()
diff --git a/wasmtime b/wasmtime
index aed6de32d..0cc4a3d44 160000
--- a/wasmtime
+++ b/wasmtime
@@ -1 +1 @@
-Subproject commit aed6de32d4e5603a7f85619d84099a9a05cb7a7c
+Subproject commit 0cc4a3d445473e3b82ae23ed13994a90b6efbea9