diff --git a/dlls/dbghelp/dbghelp.c b/dlls/dbghelp/dbghelp.c
index c006719d7aa..2651a00d47c 100644
--- a/dlls/dbghelp/dbghelp.c
+++ b/dlls/dbghelp/dbghelp.c
@@ -318,6 +318,19 @@ BOOL WINAPI SymRegisterCallback(HANDLE hProcess,
     return FALSE;
 }
 
+/***********************************************************************
+ *		SymRegisterCallback64 (DBGHELP.@)
+ */
+BOOL WINAPI SymRegisterCallback64(HANDLE hProcess, 
+                                  PSYMBOL_REGISTERED_CALLBACK64 CallbackFunction,
+                                  ULONG64 UserContext)
+{
+    FIXME("(%p, %p, %s): stub\n", 
+          hProcess, CallbackFunction, wine_dbgstr_longlong(UserContext));
+    SetLastError(ERROR_CALL_NOT_IMPLEMENTED);
+    return FALSE;
+}
+
 /* This is imagehlp version not dbghelp !! */
 static API_VERSION api_version = { 4, 0, 2, 0 };
 
diff --git a/dlls/dbghelp/dbghelp.spec b/dlls/dbghelp/dbghelp.spec
index 090ef0a6a05..361531085f4 100644
--- a/dlls/dbghelp/dbghelp.spec
+++ b/dlls/dbghelp/dbghelp.spec
@@ -75,7 +75,7 @@
 @ stub SymLoadModuleEx
 @ stdcall SymMatchFileName(str str ptr ptr)
 @ stub SymMatchString
-@ stub SymRegisterCallback64
+@ stdcall SymRegisterCallback64(long ptr double)
 @ stdcall SymRegisterCallback(long ptr ptr)
 @ stdcall SymRegisterFunctionEntryCallback64(ptr ptr double)
 @ stdcall SymRegisterFunctionEntryCallback(ptr ptr ptr)
diff --git a/include/dbghelp.h b/include/dbghelp.h
index d5849a4e1d8..1d3c8a64b50 100644
--- a/include/dbghelp.h
+++ b/include/dbghelp.h
@@ -736,6 +736,8 @@ typedef BOOL (CALLBACK *PSYM_ENUMSYMBOLS_CALLBACK)(PSTR, DWORD, ULONG, PVOID);
 BOOL WINAPI SymEnumerateSymbols(HANDLE, DWORD, PSYM_ENUMSYMBOLS_CALLBACK, PVOID);
 typedef BOOL (CALLBACK *PSYMBOL_REGISTERED_CALLBACK)(HANDLE, ULONG, PVOID, PVOID);
 BOOL WINAPI SymRegisterCallback(HANDLE, PSYMBOL_REGISTERED_CALLBACK, PVOID);
+typedef BOOL (CALLBACK *PSYMBOL_REGISTERED_CALLBACK64)(HANDLE, ULONG, ULONG64, ULONG64);
+BOOL WINAPI SymRegisterCallback64(HANDLE, PSYMBOL_REGISTERED_CALLBACK64, ULONG64);
 BOOL WINAPI SymUnDName(PIMAGEHLP_SYMBOL, PSTR, DWORD);
 DWORD WINAPI UnDecorateSymbolName(LPCSTR, LPSTR, DWORD, DWORD);