diff --git a/.github/workflows/docs.yaml b/.github/workflows/docs.yaml
index 7ae7943e..f7bc83e9 100644
--- a/.github/workflows/docs.yaml
+++ b/.github/workflows/docs.yaml
@@ -14,7 +14,7 @@ jobs:
         uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
 
       - name: Setup Python
-        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
+        uses: actions/setup-python@ece7cb06caefa5fff74198d8649806c4678c61a1 # v6.3.0
         with:
           python-version: '3.x'
           cache: "pip"
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 67c5e52e..9049b469 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -29,7 +29,7 @@ jobs:
         uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
 
       - name: Set up Python
-        uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
+        uses: actions/setup-python@ece7cb06caefa5fff74198d8649806c4678c61a1 # v6.3.0
         with:
           python-version: ${{ matrix.py }}
           allow-prereleases: true
diff --git a/.github/workflows/test_debug.yml b/.github/workflows/test_debug.yml
index 0cfb2006..4642a85c 100644
--- a/.github/workflows/test_debug.yml
+++ b/.github/workflows/test_debug.yml
@@ -13,7 +13,7 @@ jobs:
       - name: Checkout
         uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
 
-      - uses: actions/cache@27d5ce7f107fe9357f9df03efb73ab90386fccae # v5.0.5
+      - uses: actions/cache@55cc8345863c7cc4c66a329aec7e433d2d1c52a9 # v6.1.0
         with:
           path: /opt/python-debug
           key: python-debug-${{ runner.os }}-${{ env.PYTHON_VERSION }}
diff --git a/.github/workflows/wheel.yml b/.github/workflows/wheel.yml
index 8234ab4e..0e95e092 100644
--- a/.github/workflows/wheel.yml
+++ b/.github/workflows/wheel.yml
@@ -27,7 +27,7 @@ jobs:
 
     steps:
       - uses: actions/checkout@9c091bb21b7c1c1d1991bb908d89e4e9dddfe3e0 # v7.0.0
-      - uses: actions/setup-python@a309ff8b426b58ec0e2a45f0f869d46889d02405 # v6.2.0
+      - uses: actions/setup-python@ece7cb06caefa5fff74198d8649806c4678c61a1 # v6.3.0
         with:
           python-version: "3.x"
           cache: "pip"
diff --git a/msgpack/_unpacker.pyx b/msgpack/_unpacker.pyx
index f758c0c4..e0463617 100644
--- a/msgpack/_unpacker.pyx
+++ b/msgpack/_unpacker.pyx
@@ -46,7 +46,7 @@ cdef extern from "unpack.h":
         Py_ssize_t count
 
     ctypedef int (*execute_fn)(unpack_context* ctx, const char* data,
-                               Py_ssize_t len, Py_ssize_t* off) except? -1
+                               Py_ssize_t len, Py_ssize_t* off) except -1
     execute_fn unpack_construct
     execute_fn unpack_skip
     execute_fn read_array_header
@@ -206,8 +206,6 @@ def unpackb(object packed, *, object object_hook=None, object list_hook=None,
         raise FormatError
     elif ret == -3:
         raise StackError
-    elif PyErr_Occurred():
-        raise
     else:
         raise ValueError("Unpack failed: error = %d" % (ret,))
 
@@ -502,8 +500,6 @@ cdef class Unpacker:
                     raise FormatError
                 elif ret == -3:
                     raise StackError
-                elif PyErr_Occurred():
-                    raise
                 else:
                     raise ValueError("Unpack failed: error = %d" % (ret,))
         finally:
diff --git a/msgpack/unpack.h b/msgpack/unpack.h
index 55cfdab9..eb4330ac 100644
--- a/msgpack/unpack.h
+++ b/msgpack/unpack.h
@@ -40,11 +40,6 @@ struct unpack_context;
 typedef struct unpack_context unpack_context;
 typedef int (*execute_fn)(unpack_context *ctx, const char* data, Py_ssize_t len, Py_ssize_t* off);
 
-static inline msgpack_unpack_object unpack_callback_root(unpack_user* u)
-{
-    return NULL;
-}
-
 static inline int unpack_callback_uint16(unpack_user* u, uint16_t d, msgpack_unpack_object* o)
 {
     PyObject *p = PyLong_FromLong((long)d);
diff --git a/msgpack/unpack_template.h b/msgpack/unpack_template.h
index ab5887ae..797a2f91 100644
--- a/msgpack/unpack_template.h
+++ b/msgpack/unpack_template.h
@@ -35,11 +35,6 @@ struct unpack_context {
     unsigned int cs;
     unsigned int trail;
     unsigned int top;
-    /*
-    unpack_stack* stack;
-    unsigned int stack_size;
-    unpack_stack embed_stack[MSGPACK_EMBED_STACK_SIZE];
-    */
     unpack_stack stack[MSGPACK_EMBED_STACK_SIZE];
 };
 
@@ -49,22 +44,9 @@ static inline void unpack_init(unpack_context* ctx)
     ctx->cs = CS_HEADER;
     ctx->trail = 0;
     ctx->top = 0;
-    /*
-    ctx->stack = ctx->embed_stack;
-    ctx->stack_size = MSGPACK_EMBED_STACK_SIZE;
-    */
-    ctx->stack[0].obj = unpack_callback_root(&ctx->user);
+    ctx->stack[0].obj = NULL;
 }
 
-/*
-static inline void unpack_destroy(unpack_context* ctx)
-{
-    if(ctx->stack_size != MSGPACK_EMBED_STACK_SIZE) {
-        free(ctx->stack);
-    }
-}
-*/
-
 static inline PyObject* unpack_data(unpack_context* ctx)
 {
     return (ctx)->stack[0].obj;
@@ -94,9 +76,6 @@ static inline int unpack_execute(bool construct, unpack_context* ctx, const char
     unsigned int cs = ctx->cs;
     unsigned int top = ctx->top;
     unpack_stack* stack = ctx->stack;
-    /*
-    unsigned int stack_size = ctx->stack_size;
-    */
     unpack_user* user = &ctx->user;
 
     PyObject* obj = NULL;
@@ -319,6 +298,7 @@ static inline int unpack_execute(bool construct, unpack_context* ctx, const char
                 start_container(_map, _msgpack_load32(uint32_t,n), CT_MAP_KEY);
 
             default:
+                PyErr_Format(PyExc_RuntimeError, "Invalid state: %d", cs);
                 goto _failed;
             }
         }
@@ -355,6 +335,7 @@ static inline int unpack_execute(bool construct, unpack_context* ctx, const char
         goto _header_again;
 
     default:
+        PyErr_Format(PyExc_RuntimeError, "Invalid container type: %u", c->ct);
         goto _failed;
     }
 
diff --git a/test/test_unpack.py b/test/test_unpack.py
index 81bc976b..ae6ea10c 100644
--- a/test/test_unpack.py
+++ b/test/test_unpack.py
@@ -5,7 +5,15 @@
 
 from pytest import mark, raises
 
-from msgpack import ExtType, OutOfData, Unpacker, packb
+from msgpack import (
+    ExtraData,
+    ExtType,
+    OutOfData,
+    Unpacker,
+    packb,
+    unpack,
+    unpackb,
+)
 
 
 def test_unpack_array_header_from_file():
@@ -142,3 +150,20 @@ def ext_hook(code, data):
     up.feed(b"\xdc" + struct.pack(">H", 11) + b"\xd4\x05A" + b"\x2a" * 10)
     with raises(RuntimeError):
         up.unpack()
+
+
+def test_unpackb_raises_extra_data_with_trailing_bytes():
+    packed = packb(42) + packb("trailing")
+    with raises(ExtraData) as exc_info:
+        unpackb(packed)
+    err = exc_info.value
+    assert err.unpacked == 42
+    assert err.extra == packb("trailing")
+
+
+def test_unpack_raises_extra_data_on_stream_with_trailing_bytes():
+    stream = BytesIO(packb(100) + packb(200))
+    with raises(ExtraData) as exc_info:
+        unpack(stream)
+    assert exc_info.value.unpacked == 100
+    assert exc_info.value.extra == packb(200)