diff --git a/docs/modules/linalg.md b/docs/modules/linalg.md
index 3e19798a..1342ed5c 100644
--- a/docs/modules/linalg.md
+++ b/docs/modules/linalg.md
@@ -123,7 +123,7 @@ class mat3x3(_StructLike['mat3x3']):
     @overload
     def __matmul__(self, other: vec3) -> vec3: ...
 
-    def __imatmul__(self, other: mat3x3) -> None: ...
+    def __imatmul__(self, other: mat3x3): ...
     def invert_(self) -> None: ...
 
     @staticmethod
diff --git a/include/typings/linalg.pyi b/include/typings/linalg.pyi
index d72853e0..52df0d65 100644
--- a/include/typings/linalg.pyi
+++ b/include/typings/linalg.pyi
@@ -113,7 +113,7 @@ class mat3x3(_StructLike['mat3x3']):
     @overload
     def __matmul__(self, other: vec3) -> vec3: ...
 
-    def __imatmul__(self, other: mat3x3) -> None: ...
+    def __imatmul__(self, other: mat3x3): ...
     def invert_(self) -> None: ...
 
     @staticmethod
diff --git a/src/linalg.cpp b/src/linalg.cpp
index cd0476b5..1024adfe 100644
--- a/src/linalg.cpp
+++ b/src/linalg.cpp
@@ -390,7 +390,7 @@ static Vec2 SmoothDamp(Vec2 current, Vec2 target, PyVec2& currentVelocity, float
             Mat3x3 out;
             self.matmul(other, out);
             self = out;
-            return vm->None;
+            return args[0];
         });
 
         vm->bind_method<0>(type, "determinant", [](VM* vm, ArgsView args){