diff --git a/CHANGELOG.md b/CHANGELOG.md
index d1d66c1..5cf04b2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,10 +3,12 @@
 ## [Unreleased]
 **Fixes:**
 - Made `SubconParsedType` and `SubconBuildTypes` invariant.
+- Fixed return type of `Construct._build()`: `int` was wrong and worked only in specific cases.
 
 **Changes:**
 - Removed some code paths for Python versions below 3.8.
 
+
 ## [0.8.1] - 2026-07-23
 **New features:**
 - Added `Subconstruct`, `SymmetricAdapter`, `Tunnel` and `Validator` to `construct_typed` as subscriptable types.
diff --git a/construct-stubs/core.pyi b/construct-stubs/core.pyi
index 64a4b0a..b039581 100644
--- a/construct-stubs/core.pyi
+++ b/construct-stubs/core.pyi
@@ -160,9 +160,11 @@ class Construct(t.Generic[ParsedType, BuildTypes]):
     def _parsereport(
         self, stream: StreamType, context: Context, path: PathType
     ) -> ParsedType: ...
+    # In most implementations, `_build()` actually returns `ParsedType`, in some others it
+    # returns `BuildTypes` or something else entirely. `t.Any` seems a good compromise.
     def _build(
         self, obj: BuildTypes, stream: StreamType, context: Context, path: PathType
-    ) -> int: ...
+    ) -> t.Any: ...
     def _sizeof(self, context: Context, path: PathType) -> int: ...
 
 @t.type_check_only
diff --git a/tests/test_core.py b/tests/test_core.py
index aad3516..6e6b33b 100644
--- a/tests/test_core.py
+++ b/tests/test_core.py
@@ -1781,6 +1781,16 @@ def __init__(
                 hashfunc: t.Callable[[bytes], BuildTypes],
                 bytesfunc: t.Callable[[Context], bytes],
             ) -> None: ...
+
+            def _parse(self, stream: t.IO[bytes], context: Context, path: str) -> ParsedType:
+                ...
+
+            def _build(self, obj: BuildTypes, stream: t.IO[bytes], context: Context, path: str) -> t.Any:
+                ...
+
+            def _sizeof(self, context: Context, path: str) -> int:
+                ...
+
     else:
         import binascii