diff --git a/pyproject.toml b/pyproject.toml
index 948cf79..d947098 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -4,7 +4,7 @@ build-backend = "flit_core.buildapi"
 
 [project]
 name = "pytket_pecos"
-version = "0.1.10"
+version = "0.1.11"
 description = "This package enables emulation of pytket circuits using the PECOS emulator."
 authors = [{name = "Alec Edgington", email = "alec.edgington@quantinuum.com"}]
 license = {file = "LICENSE"}
diff --git a/src/pytket_pecos/emulator.py b/src/pytket_pecos/emulator.py
index 0ffe870..80eed7b 100644
--- a/src/pytket_pecos/emulator.py
+++ b/src/pytket_pecos/emulator.py
@@ -2,9 +2,11 @@
 from typing import Optional
 from pecos.engines.hybrid_engine import HybridEngine  # type: ignore
 from pecos.error_models.error_model_abc import ErrorModel  # type: ignore
+from pecos.foreign_objects.wasmtime import WasmtimeObj
 from pytket.circuit import Circuit
 from pytket.phir.api import pytket_to_phir
 from pytket.utils.outcomearray import OutcomeArray
+from pytket.wasm import WasmFileHandler
 
 
 def is_reglike(units):
@@ -20,6 +22,7 @@ class Emulator:
     def __init__(
         self,
         circuit: Circuit,
+        wasm: Optional[WasmFileHandler] = None,
         error_model: Optional[ErrorModel] = None,
         qsim: str = "stabilizer",
         seed: Optional[int] = None,
@@ -28,11 +31,14 @@ def __init__(
             raise ValueError("Circuit contains units that do not belong to a register.")
 
         self.phir = pytket_to_phir(circuit)
+        self.foreign_object = None if wasm is None else WasmtimeObj(wasm._wasm_file)
         self.engine = HybridEngine(qsim=qsim, error_model=error_model)
         self.engine.use_seed(seed)
 
     def run(self, n_shots) -> OutcomeArray:
-        results = self.engine.run(self.phir, shots=n_shots)
+        results = self.engine.run(
+            self.phir, foreign_object=self.foreign_object, shots=n_shots
+        )
         c_regs = sorted(results.keys())
         readouts = []
         for i in range(n_shots):
diff --git a/test/test_emulator.py b/test/test_emulator.py
index 964dca8..b0fe3f3 100644
--- a/test/test_emulator.py
+++ b/test/test_emulator.py
@@ -1,7 +1,9 @@
+from pathlib import Path
 import unittest
 
 from pecos.error_models.generic_error_model import GenericErrorModel  # type: ignore
-from pytket.circuit import Circuit
+from pytket.circuit import Circuit, Qubit
+from pytket.wasm import WasmFileHandler
 from pytket_pecos import Emulator
 
 
@@ -81,6 +83,18 @@ def test_setbits(self):
         result = emu.run(n_shots=1).to_intlist()[0]
         assert result == 0b110110
 
+    def test_wasm(self):
+        wasmfile = WasmFileHandler(str(Path(__file__).parent / "wasm" / "add1.wasm"))
+        c = Circuit(1)
+        a = c.add_c_register("a", 8)
+        c.add_c_setreg(23, a)
+        c.add_wasm_to_reg("add_one", wasmfile, [a], [a])
+        c.X(0)
+        c.Measure(Qubit(0), a[0])
+        emu = Emulator(c, wasm=wasmfile)
+        result = emu.run(n_shots=1).to_intlist()[0]
+        assert result == 0b10011000
+
 
 if __name__ == "__main__":
     unittest.main()
diff --git a/test/wasm/add1.c b/test/wasm/add1.c
new file mode 100644
index 0000000..5346772
--- /dev/null
+++ b/test/wasm/add1.c
@@ -0,0 +1,5 @@
+void init() {}
+
+int add_one(int n) {
+    return n + 1;
+}
diff --git a/test/wasm/add1.wasm b/test/wasm/add1.wasm
new file mode 100755
index 0000000..2e58640
Binary files /dev/null and b/test/wasm/add1.wasm differ
diff --git a/test/wasm/add1.wast b/test/wasm/add1.wast
new file mode 100644
index 0000000..b9b47f3
--- /dev/null
+++ b/test/wasm/add1.wast
@@ -0,0 +1,48 @@
+(module
+  (type (;0;) (func))
+  (type (;1;) (func (param i32) (result i32)))
+  (func $__wasm_call_ctors (type 0))
+  (func $init (type 0)
+    return)
+  (func $add_one (type 1) (param i32) (result i32)
+    (local i32 i32 i32 i32 i32 i32)
+    global.get $__stack_pointer
+    local.set 1
+    i32.const 16
+    local.set 2
+    local.get 1
+    local.get 2
+    i32.sub
+    local.set 3
+    local.get 3
+    local.get 0
+    i32.store offset=12
+    local.get 3
+    i32.load offset=12
+    local.set 4
+    i32.const 1
+    local.set 5
+    local.get 4
+    local.get 5
+    i32.add
+    local.set 6
+    local.get 6
+    return)
+  (memory (;0;) 2)
+  (global $__stack_pointer (mut i32) (i32.const 66560))
+  (global (;1;) i32 (i32.const 1024))
+  (global (;2;) i32 (i32.const 1024))
+  (global (;3;) i32 (i32.const 1024))
+  (global (;4;) i32 (i32.const 66560))
+  (global (;5;) i32 (i32.const 0))
+  (global (;6;) i32 (i32.const 1))
+  (export "memory" (memory 0))
+  (export "__wasm_call_ctors" (func $__wasm_call_ctors))
+  (export "init" (func $init))
+  (export "add_one" (func $add_one))
+  (export "__dso_handle" (global 1))
+  (export "__data_end" (global 2))
+  (export "__global_base" (global 3))
+  (export "__heap_base" (global 4))
+  (export "__memory_base" (global 5))
+  (export "__table_base" (global 6)))