diff --git a/crates/wasmparser/src/validator/component.rs b/crates/wasmparser/src/validator/component.rs
index 02f43fd349..f6fd5d3a28 100644
--- a/crates/wasmparser/src/validator/component.rs
+++ b/crates/wasmparser/src/validator/component.rs
@@ -2118,9 +2118,11 @@ impl ComponentState {
         }
 
         self.cabi_memory_at(memory, offset)?;
-
-        self.core_funcs
-            .push(types.intern_func_type(FuncType::new([ValType::I32; 2], [ValType::I32]), offset));
+        let memory64 = self.memory_at(memory, offset)?.memory64;
+        let ty = if memory64 { ValType::I64 } else { ValType::I32 };
+        self.core_funcs.push(
+            types.intern_func_type(FuncType::new([ValType::I32, ty], [ValType::I32]), offset),
+        );
         Ok(())
     }
 
@@ -2138,9 +2140,11 @@ impl ComponentState {
         }
 
         self.cabi_memory_at(memory, offset)?;
-
-        self.core_funcs
-            .push(types.intern_func_type(FuncType::new([ValType::I32; 2], [ValType::I32]), offset));
+        let memory64 = self.memory_at(memory, offset)?.memory64;
+        let ty = if memory64 { ValType::I64 } else { ValType::I32 };
+        self.core_funcs.push(
+            types.intern_func_type(FuncType::new([ValType::I32, ty], [ValType::I32]), offset),
+        );
         Ok(())
     }
 
diff --git a/crates/wit-component/src/validation.rs b/crates/wit-component/src/validation.rs
index d7565b5600..67c491c6c2 100644
--- a/crates/wit-component/src/validation.rs
+++ b/crates/wit-component/src/validation.rs
@@ -633,16 +633,16 @@ impl ImportMap {
                 return Ok(Import::WaitableSetNew);
             }
 
-            if let Some(info) = names.waitable_set_wait(name) {
-                let expected = FuncType::new([ValType::I32; 2], [ValType::I32]);
+            if let Some((info, result_ty)) = names.waitable_set_wait(name) {
+                let expected = FuncType::new([ValType::I32, result_ty], [ValType::I32]);
                 validate_func_sig(name, &expected, ty)?;
                 return Ok(Import::WaitableSetWait {
                     cancellable: info.cancellable,
                 });
             }
 
-            if let Some(info) = names.waitable_set_poll(name) {
-                let expected = FuncType::new([ValType::I32; 2], [ValType::I32]);
+            if let Some((info, result_ty)) = names.waitable_set_poll(name) {
+                let expected = FuncType::new([ValType::I32, result_ty], [ValType::I32]);
                 validate_func_sig(name, &expected, ty)?;
                 return Ok(Import::WaitableSetPoll {
                     cancellable: info.cancellable,
@@ -1580,8 +1580,8 @@ trait NameMangling {
     fn backpressure_inc(&self, name: &str) -> bool;
     fn backpressure_dec(&self, name: &str) -> bool;
     fn waitable_set_new(&self, name: &str) -> bool;
-    fn waitable_set_wait(&self, name: &str) -> Option<MaybeCancellable<()>>;
-    fn waitable_set_poll(&self, name: &str) -> Option<MaybeCancellable<()>>;
+    fn waitable_set_wait(&self, name: &str) -> Option<(MaybeCancellable<()>, ValType)>;
+    fn waitable_set_poll(&self, name: &str) -> Option<(MaybeCancellable<()>, ValType)>;
     fn waitable_set_drop(&self, name: &str) -> bool;
     fn waitable_join(&self, name: &str) -> bool;
     fn thread_yield(&self, name: &str) -> Option<MaybeCancellable<()>>;
@@ -1747,10 +1747,10 @@ impl NameMangling for Standard {
     fn waitable_set_new(&self, _name: &str) -> bool {
         false
     }
-    fn waitable_set_wait(&self, _name: &str) -> Option<MaybeCancellable<()>> {
+    fn waitable_set_wait(&self, _name: &str) -> Option<(MaybeCancellable<()>, ValType)> {
         None
     }
-    fn waitable_set_poll(&self, _name: &str) -> Option<MaybeCancellable<()>> {
+    fn waitable_set_poll(&self, _name: &str) -> Option<(MaybeCancellable<()>, ValType)> {
         None
     }
     fn waitable_set_drop(&self, _name: &str) -> bool {
@@ -2142,6 +2142,23 @@ impl Legacy {
             None
         }
     }
+
+    /// Matches a name with the given prefix and either no suffix (for backwards compat) or
+    /// "-i32" or "-i64".
+    /// Returns a `ValType` based on the suffix and defaults to `I32`.
+    fn match_with_optional_type_suffix(name: &str, match_prefix: &str) -> Option<ValType> {
+        let tail = name.strip_prefix(match_prefix)?.strip_suffix(']')?;
+        if tail.is_empty() {
+            Some(ValType::I32)
+        } else {
+            match tail.strip_prefix('-')? {
+                "i32" => Some(ValType::I32),
+                "i64" => Some(ValType::I64),
+                // Other suffixes
+                _ => None,
+            }
+        }
+    }
 }
 
 impl NameMangling for Legacy {
@@ -2196,11 +2213,23 @@ impl NameMangling for Legacy {
     fn waitable_set_new(&self, name: &str) -> bool {
         name == "[waitable-set-new]"
     }
-    fn waitable_set_wait(&self, name: &str) -> Option<MaybeCancellable<()>> {
-        self.match_with_cancellable_prefix(name, "[waitable-set-wait]")
+    fn waitable_set_wait(&self, name: &str) -> Option<(MaybeCancellable<()>, ValType)> {
+        let (cancellable, clean_name) = self.strip_cancellable_prefix(name);
+        let mb_cancellable = MaybeCancellable {
+            inner: (),
+            cancellable,
+        };
+        let result_ty = Legacy::match_with_optional_type_suffix(clean_name, "[waitable-set-wait")?;
+        Some((mb_cancellable, result_ty))
     }
-    fn waitable_set_poll(&self, name: &str) -> Option<MaybeCancellable<()>> {
-        self.match_with_cancellable_prefix(name, "[waitable-set-poll]")
+    fn waitable_set_poll(&self, name: &str) -> Option<(MaybeCancellable<()>, ValType)> {
+        let (cancellable, clean_name) = self.strip_cancellable_prefix(name);
+        let mb_cancellable = MaybeCancellable {
+            inner: (),
+            cancellable,
+        };
+        let result_ty = Legacy::match_with_optional_type_suffix(clean_name, "[waitable-set-poll")?;
+        Some((mb_cancellable, result_ty))
     }
     fn waitable_set_drop(&self, name: &str) -> bool {
         name == "[waitable-set-drop]"
diff --git a/tests/cli/component-model/memory64/waitable-set.wast b/tests/cli/component-model/memory64/waitable-set.wast
new file mode 100644
index 0000000000..00641d1e77
--- /dev/null
+++ b/tests/cli/component-model/memory64/waitable-set.wast
@@ -0,0 +1,78 @@
+;; RUN: wast --assert default --snapshot tests/snapshots % -f cm-async,cm64
+
+;; waitable-set.wait
+
+(component
+    (core module $libc (memory (export "memory") i64 1))
+    (core instance $libc (instantiate $libc))
+    (core module $m
+        (import "" "waitable-set.wait" (func $waitable-set-wait (param i32 i64) (result i32)))
+    )
+    (core func $waitable-set-wait (canon waitable-set.wait cancellable (memory $libc "memory")))
+    (core instance $i (instantiate $m (with "" (instance (export "waitable-set.wait" (func $waitable-set-wait))))))
+)
+
+(assert_invalid
+    (component
+    (core module $libc (memory (export "memory") 1))
+    (core instance $libc (instantiate $libc))
+    (core module $m
+        (import "" "waitable-set.wait" (func $waitable-set-wait (param i32 i64) (result i32)))
+    )
+    (core func $waitable-set-wait (canon waitable-set.wait cancellable (memory $libc "memory")))
+    (core instance $i (instantiate $m (with "" (instance (export "waitable-set.wait" (func $waitable-set-wait))))))
+    )
+    "type mismatch for export `waitable-set.wait`"
+)
+
+(assert_invalid
+    (component
+    (core module $libc (memory (export "memory") i64 1))
+    (core instance $libc (instantiate $libc))
+    (core module $m
+        (import "" "waitable-set.wait" (func $waitable-set-wait (param i32 i32) (result i32)))
+    )
+    (core func $waitable-set-wait (canon waitable-set.wait cancellable (memory $libc "memory")))
+    (core instance $i (instantiate $m (with "" (instance (export "waitable-set.wait" (func $waitable-set-wait))))))
+    )
+    "type mismatch for export `waitable-set.wait`"
+)
+
+
+;; waitable-set.poll
+
+(component
+    (core module $libc (memory (export "memory") i64 1))
+    (core instance $libc (instantiate $libc))
+    (core module $m
+        (import "" "waitable-set.poll" (func $waitable-set-poll (param i32 i64) (result i32)))
+    )
+    (core func $waitable-set-poll (canon waitable-set.poll cancellable (memory $libc "memory")))
+    (core instance $i (instantiate $m (with "" (instance (export "waitable-set.poll" (func $waitable-set-poll))))))
+)
+
+(assert_invalid
+    (component
+    (core module $libc (memory (export "memory") 1))
+    (core instance $libc (instantiate $libc))
+    (core module $m
+        (import "" "waitable-set.poll" (func $waitable-set-poll (param i32 i64) (result i32)))
+    )
+    (core func $waitable-set-poll (canon waitable-set.poll cancellable (memory $libc "memory")))
+    (core instance $i (instantiate $m (with "" (instance (export "waitable-set.poll" (func $waitable-set-poll))))))
+    )
+    "type mismatch for export `waitable-set.poll`"
+)
+
+(assert_invalid
+    (component
+    (core module $libc (memory (export "memory") i64 1))
+    (core instance $libc (instantiate $libc))
+    (core module $m
+        (import "" "waitable-set.poll" (func $waitable-set-poll (param i32 i32) (result i32)))
+    )
+    (core func $waitable-set-poll (canon waitable-set.poll cancellable (memory $libc "memory")))
+    (core instance $i (instantiate $m (with "" (instance (export "waitable-set.poll" (func $waitable-set-poll))))))
+    )
+    "type mismatch for export `waitable-set.poll`"
+)
\ No newline at end of file
diff --git a/tests/snapshots/cli/component-model/memory64/waitable-set.wast.json b/tests/snapshots/cli/component-model/memory64/waitable-set.wast.json
new file mode 100644
index 0000000000..30e0a4c70b
--- /dev/null
+++ b/tests/snapshots/cli/component-model/memory64/waitable-set.wast.json
@@ -0,0 +1,45 @@
+{
+  "source_filename": "tests/cli/component-model/memory64/waitable-set.wast",
+  "commands": [
+    {
+      "type": "module",
+      "line": 5,
+      "filename": "waitable-set.0.wasm",
+      "module_type": "binary"
+    },
+    {
+      "type": "assert_invalid",
+      "line": 16,
+      "filename": "waitable-set.1.wasm",
+      "module_type": "binary",
+      "text": "type mismatch for export `waitable-set.wait`"
+    },
+    {
+      "type": "assert_invalid",
+      "line": 29,
+      "filename": "waitable-set.2.wasm",
+      "module_type": "binary",
+      "text": "type mismatch for export `waitable-set.wait`"
+    },
+    {
+      "type": "module",
+      "line": 44,
+      "filename": "waitable-set.3.wasm",
+      "module_type": "binary"
+    },
+    {
+      "type": "assert_invalid",
+      "line": 55,
+      "filename": "waitable-set.4.wasm",
+      "module_type": "binary",
+      "text": "type mismatch for export `waitable-set.poll`"
+    },
+    {
+      "type": "assert_invalid",
+      "line": 68,
+      "filename": "waitable-set.5.wasm",
+      "module_type": "binary",
+      "text": "type mismatch for export `waitable-set.poll`"
+    }
+  ]
+}
\ No newline at end of file
diff --git a/tests/snapshots/cli/component-model/memory64/waitable-set.wast/0.print b/tests/snapshots/cli/component-model/memory64/waitable-set.wast/0.print
new file mode 100644
index 0000000000..c32d30e5e7
--- /dev/null
+++ b/tests/snapshots/cli/component-model/memory64/waitable-set.wast/0.print
@@ -0,0 +1,20 @@
+(component
+  (core module $libc (;0;)
+    (memory (;0;) i64 1)
+    (export "memory" (memory 0))
+  )
+  (core instance $libc (;0;) (instantiate $libc))
+  (core module $m (;1;)
+    (type (;0;) (func (param i32 i64) (result i32)))
+    (import "" "waitable-set.wait" (func $waitable-set-wait (;0;) (type 0)))
+  )
+  (alias core export $libc "memory" (core memory (;0;)))
+  (core func $waitable-set-wait (;0;) (canon waitable-set.wait cancellable (memory 0)))
+  (core instance (;1;)
+    (export "waitable-set.wait" (func $waitable-set-wait))
+  )
+  (core instance $i (;2;) (instantiate $m
+      (with "" (instance 1))
+    )
+  )
+)
diff --git a/tests/snapshots/cli/component-model/memory64/waitable-set.wast/3.print b/tests/snapshots/cli/component-model/memory64/waitable-set.wast/3.print
new file mode 100644
index 0000000000..849528e4bb
--- /dev/null
+++ b/tests/snapshots/cli/component-model/memory64/waitable-set.wast/3.print
@@ -0,0 +1,20 @@
+(component
+  (core module $libc (;0;)
+    (memory (;0;) i64 1)
+    (export "memory" (memory 0))
+  )
+  (core instance $libc (;0;) (instantiate $libc))
+  (core module $m (;1;)
+    (type (;0;) (func (param i32 i64) (result i32)))
+    (import "" "waitable-set.poll" (func $waitable-set-poll (;0;) (type 0)))
+  )
+  (alias core export $libc "memory" (core memory (;0;)))
+  (core func $waitable-set-poll (;0;) (canon waitable-set.poll cancellable (memory 0)))
+  (core instance (;1;)
+    (export "waitable-set.poll" (func $waitable-set-poll))
+  )
+  (core instance $i (;2;) (instantiate $m
+      (with "" (instance 1))
+    )
+  )
+)