diff --git a/master/custom/builders.py b/master/custom/builders.py
index 4956d2b4..9d5822c1 100644
--- a/master/custom/builders.py
+++ b/master/custom/builders.py
@@ -43,7 +43,7 @@
     WindowsARM64Build,
     WindowsARM64ReleaseBuild,
     Wasm32WasiCrossBuild,
-    Wasm32WasiDebugBuild,
+    Wasm32WasiPreview1DebugBuild,
     IOSARM64SimulatorBuild,
     AndroidBuild,
     ValgrindBuild,
@@ -133,7 +133,7 @@
 
     # WASI
     ("wasm32-wasi Non-Debug", "bcannon-wasi", Wasm32WasiCrossBuild),
-    ("wasm32-wasi", "bcannon-wasi", Wasm32WasiDebugBuild),
+    ("wasm32-wasi", "bcannon-wasi", Wasm32WasiPreview1DebugBuild),
 ]
 
 
diff --git a/master/custom/factories.py b/master/custom/factories.py
index 003473b9..6d6bb87c 100644
--- a/master/custom/factories.py
+++ b/master/custom/factories.py
@@ -872,7 +872,7 @@ def setup(self, parallel, branch, test_with_PTY=False, **kwargs):
         super().setup(parallel, branch, test_with_PTY=test_with_PTY, **kwargs)
 
 
-class _Wasm32WasiBuild(UnixBuild):
+class _Wasm32WasiPreview1Build(UnixBuild):
     """Build Python for wasm32-wasi using Tools/wasm/wasi.py."""
     buildersuffix = ".wasi"
     factory_tags = ["wasm", "wasi"]
@@ -886,7 +886,8 @@ def __init__(self, source, *, extra_tags=[], **kwargs):
 
     def setup(self, parallel, branch, test_with_PTY=False, **kwargs):
         wasi_py = "Tools/wasm/wasi.py"
-        host_path = "build/cross-build/wasm32-wasi"
+        host_triple = "wasm32-wasip1"
+        host_path = f"build/cross-build/{host_triple}"
 
         # Build Python
         build_configure = ["python3", wasi_py, "configure-build-python"]
@@ -968,7 +969,7 @@ def setup(self, parallel, branch, test_with_PTY=False, **kwargs):
 
 # Preventing this from running on versions older than 3.13 is managed in
 # master.cfg.
-class Wasm32WasiDebugBuild(_Wasm32WasiBuild):
+class Wasm32WasiPreview1DebugBuild(_Wasm32WasiPreview1Build):
     append_suffix = ".debug"
     pydebug = True
     testFlags = ["-u-cpu"]