diff --git a/dlls/atlthunk/atlthunk.c b/dlls/atlthunk/atlthunk.c
index 79d04323001..cd37b75f040 100644
--- a/dlls/atlthunk/atlthunk.c
+++ b/dlls/atlthunk/atlthunk.c
@@ -22,24 +22,164 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL(atlthunk);
 
+#if defined(__i386__) || defined(__x86_64__)
+
+struct AtlThunkData_t {
+    struct thunk_pool *pool;
+    WNDPROC proc;
+    SIZE_T arg;
+};
+
+/* Thunk replaces the first argument and jumps to provided proc. */
+#include "pshpack1.h"
+struct thunk_code
+{
+#if defined(__x86_64__)
+    BYTE  mov_rip_rcx[3];     /* mov mov_offset(%rip), %rcx */
+    DWORD mov_offset;
+    WORD  jmp_rip;            /* jmp *jmp_offset(%rip) */
+    DWORD jmp_offset;
+#elif defined(__i386__)
+    BYTE  mov_data_addr_eax;  /* movl data_addr, %eax */
+    DWORD data_addr;
+    DWORD mov_eax_esp;        /* movl %eax, 4(%esp) */
+    WORD  jmp;
+    DWORD jmp_addr;           /* jmp *jmp_addr */
+#endif
+};
+#include "poppack.h"
+
+#define THUNK_POOL_SIZE (4096 / sizeof(struct thunk_code))
+
+struct thunk_pool
+{
+    struct thunk_code thunks[THUNK_POOL_SIZE];
+    LONG first_free;
+    LONG free_count;
+    AtlThunkData_t data[THUNK_POOL_SIZE];
+};
+
+C_ASSERT(FIELD_OFFSET(struct thunk_pool, first_free) == 4096);
+
+static struct thunk_pool *alloc_thunk_pool(void)
+{
+    struct thunk_pool *thunks;
+    DWORD old_protect;
+    unsigned i;
+
+    if (!(thunks = VirtualAlloc(NULL, sizeof(*thunks), MEM_COMMIT, PAGE_READWRITE)))
+        return NULL;
+
+    for (i = 0; i < ARRAY_SIZE(thunks->thunks); i++)
+    {
+        struct thunk_code *thunk = &thunks->thunks[i];
+#if defined(__x86_64__)
+        thunk->mov_rip_rcx[0]    = 0x48;    /* mov mov_offset(%rip), %rcx */
+        thunk->mov_rip_rcx[1]    = 0x8b;
+        thunk->mov_rip_rcx[2]    = 0x0d;
+        thunk->mov_offset = (const BYTE *)&thunks->data[i].arg - (const BYTE *)(&thunk->mov_offset + 1);
+        thunk->jmp_rip           = 0x25ff;  /* jmp *jmp_offset(%rip) */
+        thunk->jmp_offset = (const BYTE *)&thunks->data[i].proc - (const BYTE *)(&thunk->jmp_offset + 1);
+#elif defined(__i386__)
+        thunk->mov_data_addr_eax = 0xa1;       /* movl data_addr, %eax */
+        thunk->data_addr         = (DWORD)&thunks->data[i].arg;
+        thunk->mov_eax_esp       = 0x04244489; /* movl %eax, 4(%esp) */
+        thunk->jmp               = 0x25ff;     /* jmp *jmp_addr */
+        thunk->jmp_addr          = (DWORD)&thunks->data[i].proc;
+#endif
+    }
+    VirtualProtect(thunks->thunks, FIELD_OFFSET(struct thunk_pool, first_free), PAGE_EXECUTE_READ, &old_protect);
+    thunks->first_free = 0;
+    thunks->free_count = 0;
+    return thunks;
+}
+
+static struct thunk_pool *current_pool;
+
+BOOL WINAPI DllMain(HINSTANCE instance, DWORD reason, LPVOID reserved)
+{
+    switch (reason)
+    {
+    case DLL_PROCESS_ATTACH:
+        DisableThreadLibraryCalls(instance);
+        break;
+    case DLL_PROCESS_DETACH:
+        if (reserved) break;
+        if (current_pool && current_pool->free_count == current_pool->first_free)
+            VirtualFree(current_pool, sizeof(*current_pool), MEM_RELEASE);
+        break;
+    }
+    return TRUE;
+}
+
+static CRITICAL_SECTION thunk_alloc_cs;
+static CRITICAL_SECTION_DEBUG thunk_alloc_cs_debug = {
+    0, 0, &thunk_alloc_cs,
+    { &thunk_alloc_cs_debug.ProcessLocksList,
+      &thunk_alloc_cs_debug.ProcessLocksList },
+    0, 0, { (DWORD_PTR)(__FILE__ ": thunk_alloc_cs") }
+};
+static CRITICAL_SECTION thunk_alloc_cs = { &thunk_alloc_cs_debug, -1, 0, 0, 0, 0 };
+
 AtlThunkData_t* WINAPI AtlThunk_AllocateData(void)
 {
-    FIXME("\n");
+    AtlThunkData_t *thunk = NULL;
+
+    EnterCriticalSection(&thunk_alloc_cs);
+
+    if (!current_pool) current_pool = alloc_thunk_pool();
+    if (current_pool)
+    {
+        thunk = &current_pool->data[current_pool->first_free];
+        thunk->pool = current_pool;
+        thunk->proc = NULL;
+        thunk->arg  = 0;
+        if (++current_pool->first_free == ARRAY_SIZE(current_pool->data))
+            current_pool = NULL;
+    }
+
+    LeaveCriticalSection(&thunk_alloc_cs);
+    return thunk;
+}
+
+WNDPROC WINAPI AtlThunk_DataToCode(AtlThunkData_t *thunk)
+{
+    WNDPROC code = (WNDPROC)&thunk->pool->thunks[thunk - thunk->pool->data];
+    TRACE("(%p) -> %p\n", thunk, code);
+    return code;
+}
+
+void WINAPI AtlThunk_FreeData(AtlThunkData_t *thunk)
+{
+    if (InterlockedIncrement(&thunk->pool->free_count) == ARRAY_SIZE(thunk->pool->thunks))
+        VirtualFree(thunk->pool, sizeof(*thunk->pool), MEM_RELEASE);
+}
+
+void WINAPI AtlThunk_InitData(AtlThunkData_t *thunk, void *proc, SIZE_T arg)
+{
+    thunk->proc = proc;
+    thunk->arg = arg;
+}
+
+#else  /* __i386__ || __x86_64__ */
+
+AtlThunkData_t* WINAPI AtlThunk_AllocateData(void)
+{
+    FIXME("Unsupported architecture.\n");
     return NULL;
 }
 
 WNDPROC WINAPI AtlThunk_DataToCode(AtlThunkData_t *thunk)
 {
-    FIXME("(%p)\n", thunk);
     return NULL;
 }
 
 void WINAPI AtlThunk_FreeData(AtlThunkData_t *thunk)
 {
-    FIXME("(%p)\n", thunk);
 }
 
 void WINAPI AtlThunk_InitData(AtlThunkData_t *thunk, void *proc, SIZE_T arg)
 {
-    FIXME("(%p %p %lx)\n", thunk, proc, arg);
 }
+
+#endif  /* __i386__ || __x86_64__ */