diff --git a/dlls/dbghelp/dbghelp.spec b/dlls/dbghelp/dbghelp.spec
index cff2ab7efb3..ae911b7db02 100644
--- a/dlls/dbghelp/dbghelp.spec
+++ b/dlls/dbghelp/dbghelp.spec
@@ -86,7 +86,7 @@
 @ stub SymSetSymWithAddr64
 @ stub SymUnDName64
 @ stdcall SymUnDName(ptr str long)
-@ stub SymUnloadModule64
+@ stdcall SymUnloadModule64(long double)
 @ stdcall SymUnloadModule(long long)
 @ stdcall UnDecorateSymbolName(str str long long)
 @ stdcall UnmapDebugInformation(ptr)
diff --git a/dlls/dbghelp/module.c b/dlls/dbghelp/module.c
index 18e01629bff..e39f431c7b8 100644
--- a/dlls/dbghelp/module.c
+++ b/dlls/dbghelp/module.c
@@ -446,6 +446,23 @@ BOOL WINAPI SymUnloadModule(HANDLE hProcess, DWORD BaseOfDll)
     return module_remove(pcs, module);
 }
 
+/******************************************************************
+ *		SymUnloadModule64 (DBGHELP.@)
+ *
+ */
+BOOL WINAPI SymUnloadModule64(HANDLE hProcess, DWORD64 BaseOfDll)
+{
+    struct process*     pcs;
+    struct module*      module;
+
+    pcs = process_find_by_handle(hProcess);
+    if (!pcs) return FALSE;
+    if (!validate_addr64(BaseOfDll)) return FALSE;
+    module = module_find_by_addr(pcs, (DWORD)BaseOfDll, DMT_UNKNOWN);
+    if (!module) return FALSE;
+    return module_remove(pcs, module);
+}
+
 /******************************************************************
  *		SymEnumerateModules (DBGHELP.@)
  *
diff --git a/include/dbghelp.h b/include/dbghelp.h
index 734af1576b3..044e2bf324c 100644
--- a/include/dbghelp.h
+++ b/include/dbghelp.h
@@ -617,6 +617,7 @@ DWORD   WINAPI SymLoadModule(HANDLE, HANDLE, PSTR, PSTR, DWORD, DWORD);
 DWORD64 WINAPI SymLoadModuleEx(HANDLE, HANDLE, PCSTR, PCSTR, DWORD64, DWORD,
                                PMODLOAD_DATA, DWORD);
 BOOL    WINAPI SymUnloadModule(HANDLE, DWORD);
+BOOL    WINAPI SymUnloadModule64(HANDLE, DWORD64);
 
 /*************************
  *    Symbol Handling    *