diff --git a/dlls/msvcirt/msvcirt.c b/dlls/msvcirt/msvcirt.c
index 72146998a5d..a6d37496089 100644
--- a/dlls/msvcirt/msvcirt.c
+++ b/dlls/msvcirt/msvcirt.c
@@ -385,6 +385,24 @@ int __thiscall streambuf_sync(streambuf *this)
     return EOF;
 }
 
+/* ?unbuffered@streambuf@@IAEXH@Z */
+/* ?unbuffered@streambuf@@IEAAXH@Z */
+DEFINE_THISCALL_WRAPPER(streambuf_unbuffered_set, 8)
+void __thiscall streambuf_unbuffered_set(streambuf *this, int buf)
+{
+    TRACE("(%p %d)\n", this, buf);
+    this->unbuffered = buf;
+}
+
+/* ?unbuffered@streambuf@@IBEHXZ */
+/* ?unbuffered@streambuf@@IEBAHXZ */
+DEFINE_THISCALL_WRAPPER(streambuf_unbuffered_get, 4)
+int __thiscall streambuf_unbuffered_get(const streambuf *this)
+{
+    TRACE("(%p)\n", this);
+    return this->unbuffered;
+}
+
 /* Unexported */
 DEFINE_THISCALL_WRAPPER(streambuf_underflow, 4)
 int __thiscall streambuf_underflow(streambuf *this)
diff --git a/dlls/msvcirt/msvcirt.spec b/dlls/msvcirt/msvcirt.spec
index 9ab9adfd944..8a57404bb31 100644
--- a/dlls/msvcirt/msvcirt.spec
+++ b/dlls/msvcirt/msvcirt.spec
@@ -741,10 +741,10 @@
 @ stub -arch=win64 ?tie@ios@@QEAAPEAVostream@@PEAV2@@Z
 @ stub -arch=win32 ?tie@ios@@QBEPAVostream@@XZ  # class ostream * __thiscall ios::tie(void)const 
 @ stub -arch=win64 ?tie@ios@@QEBAPEAVostream@@XZ
-@ stub -arch=win32 ?unbuffered@streambuf@@IAEXH@Z  # void __thiscall streambuf::unbuffered(int)
-@ stub -arch=win64 ?unbuffered@streambuf@@IEAAXH@Z
-@ stub -arch=win32 ?unbuffered@streambuf@@IBEHXZ  # int __thiscall streambuf::unbuffered(void)const 
-@ stub -arch=win64 ?unbuffered@streambuf@@IEBAHXZ
+@ thiscall -arch=win32 ?unbuffered@streambuf@@IAEXH@Z(ptr long) streambuf_unbuffered_set
+@ cdecl -arch=win64 ?unbuffered@streambuf@@IEAAXH@Z(ptr long) streambuf_unbuffered_set
+@ thiscall -arch=win32 ?unbuffered@streambuf@@IBEHXZ(ptr) streambuf_unbuffered_get
+@ cdecl -arch=win64 ?unbuffered@streambuf@@IEBAHXZ(ptr) streambuf_unbuffered_get
 @ stub -arch=win32 ?underflow@filebuf@@UAEHXZ  # virtual int __thiscall filebuf::underflow(void)
 @ stub -arch=win64 ?underflow@filebuf@@UEAAHXZ
 @ stub -arch=win32 ?underflow@stdiobuf@@UAEHXZ  # virtual int __thiscall stdiobuf::underflow(void)
diff --git a/dlls/msvcrt20/msvcrt20.spec b/dlls/msvcrt20/msvcrt20.spec
index 36dffbd8be8..2c609647bb4 100644
--- a/dlls/msvcrt20/msvcrt20.spec
+++ b/dlls/msvcrt20/msvcrt20.spec
@@ -730,10 +730,10 @@
 @ stub -arch=win64 ?tie@ios@@QEAAPEAVostream@@PEAV2@@Z
 @ stub -arch=win32 ?tie@ios@@QBEPAVostream@@XZ
 @ stub -arch=win64 ?tie@ios@@QEBAPEAVostream@@XZ
-@ stub -arch=win32 ?unbuffered@streambuf@@IAEXH@Z
-@ stub -arch=win64 ?unbuffered@streambuf@@IEAAXH@Z
-@ stub -arch=win32 ?unbuffered@streambuf@@IBEHXZ
-@ stub -arch=win64 ?unbuffered@streambuf@@IEBAHXZ
+@ thiscall -arch=win32 ?unbuffered@streambuf@@IAEXH@Z(ptr long) msvcirt.?unbuffered@streambuf@@IAEXH@Z
+@ cdecl -arch=win64 ?unbuffered@streambuf@@IEAAXH@Z(ptr long) msvcirt.?unbuffered@streambuf@@IEAAXH@Z
+@ thiscall -arch=win32 ?unbuffered@streambuf@@IBEHXZ(ptr) msvcirt.?unbuffered@streambuf@@IBEHXZ
+@ cdecl -arch=win64 ?unbuffered@streambuf@@IEBAHXZ(ptr) msvcirt.?unbuffered@streambuf@@IEBAHXZ
 @ stub -arch=win32 ?underflow@filebuf@@UAEHXZ
 @ stub -arch=win64 ?underflow@filebuf@@UEAAHXZ
 @ stub -arch=win32 ?underflow@stdiobuf@@UAEHXZ
diff --git a/dlls/msvcrt40/msvcrt40.spec b/dlls/msvcrt40/msvcrt40.spec
index 4ae2ff41d3e..a029b1bec9e 100644
--- a/dlls/msvcrt40/msvcrt40.spec
+++ b/dlls/msvcrt40/msvcrt40.spec
@@ -802,10 +802,10 @@
 @ stub -arch=win64 ?tie@ios@@QEAAPEAVostream@@PEAV2@@Z
 @ stub -arch=win32 ?tie@ios@@QBEPAVostream@@XZ
 @ stub -arch=win64 ?tie@ios@@QEBAPEAVostream@@XZ
-@ stub -arch=win32 ?unbuffered@streambuf@@IAEXH@Z
-@ stub -arch=win64 ?unbuffered@streambuf@@IEAAXH@Z
-@ stub -arch=win32 ?unbuffered@streambuf@@IBEHXZ
-@ stub -arch=win64 ?unbuffered@streambuf@@IEBAHXZ
+@ thiscall -arch=win32 ?unbuffered@streambuf@@IAEXH@Z(ptr long) msvcirt.?unbuffered@streambuf@@IAEXH@Z
+@ cdecl -arch=win64 ?unbuffered@streambuf@@IEAAXH@Z(ptr long) msvcirt.?unbuffered@streambuf@@IEAAXH@Z
+@ thiscall -arch=win32 ?unbuffered@streambuf@@IBEHXZ(ptr) msvcirt.?unbuffered@streambuf@@IBEHXZ
+@ cdecl -arch=win64 ?unbuffered@streambuf@@IEBAHXZ(ptr) msvcirt.?unbuffered@streambuf@@IEBAHXZ
 @ stub -arch=win32 ?underflow@filebuf@@UAEHXZ
 @ stub -arch=win64 ?underflow@filebuf@@UEAAHXZ
 @ stub -arch=win32 ?underflow@stdiobuf@@UAEHXZ