diff --git a/dlls/comctl32/dpa.c b/dlls/comctl32/dpa.c
index def2e9596ef..f9c8afc8bd9 100644
--- a/dlls/comctl32/dpa.c
+++ b/dlls/comctl32/dpa.c
@@ -61,15 +61,6 @@ typedef struct _STREAMDATA
     DWORD dwItems;
 } STREAMDATA, *PSTREAMDATA;
 
-typedef struct _LOADDATA
-{
-    INT   nCount;
-    PVOID ptr;
-} LOADDATA, *LPLOADDATA;
-
-typedef HRESULT (CALLBACK *DPALOADPROC)(LPLOADDATA,IStream*,LPARAM);
-
-
 /**************************************************************************
  * DPA_LoadStream [COMCTL32.9]
  *
@@ -79,29 +70,29 @@ typedef HRESULT (CALLBACK *DPALOADPROC)(LPLOADDATA,IStream*,LPARAM);
  *     phDpa    [O] pointer to a handle to a dynamic pointer array
  *     loadProc [I] pointer to a callback function
  *     pStream  [I] pointer to a stream
- *     lParam   [I] application specific value
+ *     pData    [I] pointer to callback data
  *
  * RETURNS
  *     Success: TRUE
- *     Failure: FALSE 
+ *     Failure: FALSE
  *
  * NOTES
  *     No more information available yet!
  */
-HRESULT WINAPI DPA_LoadStream (HDPA *phDpa, DPALOADPROC loadProc,
-                               IStream *pStream, LPARAM lParam)
+HRESULT WINAPI DPA_LoadStream (HDPA *phDpa, PFNDPASTREAM loadProc,
+                               IStream *pStream, LPVOID pData)
 {
     HRESULT errCode;
     LARGE_INTEGER position;
     ULARGE_INTEGER newPosition;
     STREAMDATA  streamData;
-    LOADDATA loadData;
+    DPASTREAMINFO streamInfo;
     ULONG ulRead;
     HDPA hDpa;
     PVOID *ptr;
 
-    FIXME ("phDpa=%p loadProc=%p pStream=%p lParam=%lx\n",
-           phDpa, loadProc, pStream, lParam);
+    FIXME ("phDpa=%p loadProc=%p pStream=%p pData=%p\n",
+           phDpa, loadProc, pStream, pData);
 
     if (!phDpa || !loadProc || !pStream)
         return E_INVALIDARG;
@@ -127,7 +118,7 @@ HRESULT WINAPI DPA_LoadStream (HDPA *phDpa, DPALOADPROC loadProc,
            streamData.dwSize, streamData.dwData2, streamData.dwItems);
 
     if ( ulRead < sizeof(STREAMDATA) ||
-    lParam < sizeof(STREAMDATA) ||
+    (DWORD)pData < sizeof(STREAMDATA) ||
         streamData.dwSize < sizeof(STREAMDATA) ||
         streamData.dwData2 < 1) {
         errCode = E_FAIL;
@@ -146,19 +137,19 @@ HRESULT WINAPI DPA_LoadStream (HDPA *phDpa, DPALOADPROC loadProc,
 
     /* load data from the stream into the dpa */
     ptr = hDpa->ptrs;
-    for (loadData.nCount = 0; loadData.nCount < streamData.dwItems; loadData.nCount++) {
-        errCode = (loadProc)(&loadData, pStream, lParam);
+    for (streamInfo.iPos = 0; streamInfo.iPos < streamData.dwItems; streamInfo.iPos++) {
+        errCode = (loadProc)(&streamInfo, pStream, pData);
         if (errCode != S_OK) {
             errCode = S_FALSE;
             break;
         }
 
-        *ptr = loadData.ptr;
+        *ptr = streamInfo.pvItem;
         ptr++;
     }
 
     /* set the number of items */
-    hDpa->nItemCount = loadData.nCount;
+    hDpa->nItemCount = streamInfo.iPos;
 
     /* store the handle to the dpa */
     *phDpa = hDpa;
@@ -177,21 +168,21 @@ HRESULT WINAPI DPA_LoadStream (HDPA *phDpa, DPALOADPROC loadProc,
  *     hDpa     [I] handle to a dynamic pointer array
  *     loadProc [I] pointer to a callback function
  *     pStream  [I] pointer to a stream
- *     lParam   [I] application specific value
+ *     pData    [I] pointer to callback data
  *
  * RETURNS
  *     Success: TRUE
- *     Failure: FALSE 
+ *     Failure: FALSE
  *
  * NOTES
  *     No more information available yet!
  */
-HRESULT WINAPI DPA_SaveStream (const HDPA hDpa, DPALOADPROC loadProc,
-                               IStream *pStream, LPARAM lParam)
+HRESULT WINAPI DPA_SaveStream (const HDPA hDpa, PFNDPASTREAM loadProc,
+                               IStream *pStream, LPVOID pData)
 {
 
-    FIXME ("hDpa=%p loadProc=%p pStream=%p lParam=%lx\n",
-           hDpa, loadProc, pStream, lParam);
+    FIXME ("hDpa=%p loadProc=%p pStream=%p pData=%p\n",
+           hDpa, loadProc, pStream, pData);
 
     return E_FAIL;
 }
diff --git a/dlls/comctl32/tests/dpa.c b/dlls/comctl32/tests/dpa.c
index d7de37710c7..e9a1fa5b965 100644
--- a/dlls/comctl32/tests/dpa.c
+++ b/dlls/comctl32/tests/dpa.c
@@ -33,14 +33,6 @@
 
 #define expect(expected, got) ok(got == expected, "Expected %d, got %d\n", expected, got)
 
-typedef struct _ITEMDATA
-{
-    INT   iPos;
-    PVOID pvData;
-} ITEMDATA, *LPITEMDATA;
-
-typedef HRESULT (CALLBACK *PFNDPASTM)(LPITEMDATA,IStream*,LPARAM);
-
 static HDPA    (WINAPI *pDPA_Clone)(const HDPA,const HDPA);
 static HDPA    (WINAPI *pDPA_Create)(INT);
 static HDPA    (WINAPI *pDPA_CreateEx)(INT,HANDLE);
@@ -53,9 +45,9 @@ static INT     (WINAPI *pDPA_GetPtr)(const HDPA,INT);
 static INT     (WINAPI *pDPA_GetPtrIndex)(const HDPA,PVOID);
 static BOOL    (WINAPI *pDPA_Grow)(HDPA,INT);
 static INT     (WINAPI *pDPA_InsertPtr)(const HDPA,INT,PVOID);
-static HRESULT (WINAPI *pDPA_LoadStream)(HDPA*,PFNDPASTM,IStream*,LPARAM);
+static HRESULT (WINAPI *pDPA_LoadStream)(HDPA*,PFNDPASTREAM,IStream*,LPARAM);
 static BOOL    (WINAPI *pDPA_Merge)(const HDPA,const HDPA,DWORD,PFNDPACOMPARE,PFNDPAMERGE,LPARAM);
-static HRESULT (WINAPI *pDPA_SaveStream)(HDPA,PFNDPASTM,IStream*,LPARAM);
+static HRESULT (WINAPI *pDPA_SaveStream)(HDPA,PFNDPASTREAM,IStream*,LPARAM);
 static INT     (WINAPI *pDPA_Search)(HDPA,PVOID,INT,PFNDPACOMPARE,LPARAM,UINT);
 static BOOL    (WINAPI *pDPA_SetPtr)(const HDPA,INT,PVOID);
 static BOOL    (WINAPI *pDPA_Sort)(const HDPA,PFNDPACOMPARE,LPARAM);
@@ -140,29 +132,29 @@ static INT CALLBACK CB_EnumFirstThree(PVOID pItem, PVOID lp)
     return pItem != (PVOID)3;
 }
 
-static HRESULT CALLBACK CB_Save(LPITEMDATA pInfo, IStream *pStm, LPARAM lp)
+static HRESULT CALLBACK CB_Save(DPASTREAMINFO *pInfo, IStream *pStm, LPVOID lp)
 {
     HRESULT hRes;
     
-    ok(lp == 0xdeadbeef, "lp=%ld\n", lp);
+    ok(lp == (LPVOID)0xdeadbeef, "lp=%p\n", lp);
     hRes = IStream_Write(pStm, &pInfo->iPos, sizeof(INT), NULL);
     ok(hRes == S_OK, "hRes=0x%x\n", hRes);
-    hRes = IStream_Write(pStm, &pInfo->pvData, sizeof(PVOID), NULL);
+    hRes = IStream_Write(pStm, &pInfo->pvItem, sizeof(PVOID), NULL);
     ok(hRes == S_OK, "hRes=0x%x\n", hRes);
     return S_OK;
 }
 
-static HRESULT CALLBACK CB_Load(LPITEMDATA pInfo, IStream *pStm, LPARAM lp)
+static HRESULT CALLBACK CB_Load(DPASTREAMINFO *pInfo, IStream *pStm, LPVOID lp)
 {
     HRESULT hRes;
     INT iOldPos;
     
     iOldPos = pInfo->iPos;
-    ok(lp == 0xdeadbeef, "lp=%ld\n", lp);
+    ok(lp == (LPVOID)0xdeadbeef, "lp=%p\n", lp);
     hRes = IStream_Read(pStm, &pInfo->iPos, sizeof(INT), NULL);
     ok(hRes == S_OK, "hRes=0x%x\n", hRes);
     ok(pInfo->iPos == iOldPos, "iPos=%d iOldPos=%d\n", pInfo->iPos, iOldPos);
-    hRes = IStream_Read(pStm, &pInfo->pvData, sizeof(PVOID), NULL);
+    hRes = IStream_Read(pStm, &pInfo->pvItem, sizeof(PVOID), NULL);
     ok(hRes == S_OK, "hRes=0x%x\n", hRes);
     return S_OK;
 }
diff --git a/include/commctrl.h b/include/commctrl.h
index 55cae1c5f7d..bda13de44a2 100644
--- a/include/commctrl.h
+++ b/include/commctrl.h
@@ -5011,6 +5011,19 @@ void   WINAPI DPA_DestroyCallback(HDPA, PFNDPAENUMCALLBACK, LPVOID);
 INT    WINAPI DPA_Search(HDPA, LPVOID, INT, PFNDPACOMPARE, LPARAM, UINT);
 BOOL   WINAPI DPA_Merge(HDPA, HDPA, DWORD, PFNDPACOMPARE, PFNDPAMERGE, LPARAM);
 
+/* save/load from stream */
+typedef struct _DPASTREAMINFO
+{
+    INT    iPos;   /* item index */
+    LPVOID pvItem;
+} DPASTREAMINFO;
+
+struct IStream;
+typedef HRESULT (CALLBACK *PFNDPASTREAM)(DPASTREAMINFO*, struct IStream*, LPVOID);
+
+HRESULT WINAPI DPA_LoadStream(HDPA*, PFNDPASTREAM, struct IStream*, LPVOID);
+HRESULT WINAPI DPA_SaveStream(HDPA, PFNDPASTREAM, struct IStream*, LPVOID);
+
 BOOL WINAPI Str_SetPtrW (LPWSTR *, LPCWSTR);
 
 /**************************************************************************