diff --git a/dlls/windowscodecs/icoformat.c b/dlls/windowscodecs/icoformat.c
index ec09aa6778..d24503118c 100644
--- a/dlls/windowscodecs/icoformat.c
+++ b/dlls/windowscodecs/icoformat.c
@@ -293,7 +293,7 @@ static HRESULT ReadIcoDib(IStream *stream, IcoFrameDecode *result)
         {
             /* If the alpha channel is fully transparent, we should ignore it. */
             int nonzero_alpha = 0;
-            int i;
+            UINT i;
 
             for (i=0; i<(result->height*result->width); i++)
             {
diff --git a/dlls/windowscodecs/info.c b/dlls/windowscodecs/info.c
index 3da5b20741..7c87c5d77e 100644
--- a/dlls/windowscodecs/info.c
+++ b/dlls/windowscodecs/info.c
@@ -539,7 +539,8 @@ static HRESULT WINAPI BitmapDecoderInfo_MatchesPattern(IWICBitmapDecoderInfo *if
     WICBitmapPattern *patterns;
     UINT pattern_count=0, patterns_size=0;
     HRESULT hr;
-    int i, pos;
+    UINT i;
+    ULONG pos;
     BYTE *data=NULL;
     ULONG datasize=0;
     ULONG bytesread;
@@ -1900,7 +1901,7 @@ static HRESULT WINAPI ComponentEnum_Next(IEnumUnknown *iface, ULONG celt,
     IUnknown **rgelt, ULONG *pceltFetched)
 {
     ComponentEnum *This = impl_from_IEnumUnknown(iface);
-    int num_fetched=0;
+    ULONG num_fetched=0;
     ComponentEnumItem *item;
     HRESULT hr=S_OK;
 
@@ -1929,7 +1930,7 @@ static HRESULT WINAPI ComponentEnum_Next(IEnumUnknown *iface, ULONG celt,
 static HRESULT WINAPI ComponentEnum_Skip(IEnumUnknown *iface, ULONG celt)
 {
     ComponentEnum *This = impl_from_IEnumUnknown(iface);
-    int i;
+    ULONG i;
     HRESULT hr=S_OK;
 
     TRACE("(%p,%u)\n", iface, celt);
diff --git a/dlls/windowscodecs/jpegformat.c b/dlls/windowscodecs/jpegformat.c
index 1aca6d1a76..6f2653dc4d 100644
--- a/dlls/windowscodecs/jpegformat.c
+++ b/dlls/windowscodecs/jpegformat.c
@@ -998,7 +998,8 @@ static HRESULT WINAPI JpegEncoder_Frame_WritePixels(IWICBitmapFrameEncode *iface
     JpegEncoder *This = impl_from_IWICBitmapFrameEncode(iface);
     jmp_buf jmpbuf;
     BYTE *swapped_data = NULL, *current_row;
-    int line, row_size;
+    UINT line;
+    int row_size;
     TRACE("(%p,%u,%u,%u,%p)\n", iface, lineCount, cbStride, cbBufferSize, pbPixels);
 
     EnterCriticalSection(&This->lock);
@@ -1061,7 +1062,7 @@ static HRESULT WINAPI JpegEncoder_Frame_WritePixels(IWICBitmapFrameEncode *iface
     {
         if (This->format->swap_rgb)
         {
-            int x;
+            UINT x;
 
             memcpy(swapped_data, pbPixels + (cbStride * line), row_size);
 
diff --git a/dlls/windowscodecs/main.c b/dlls/windowscodecs/main.c
index b63edf50f7..967f80b2ea 100644
--- a/dlls/windowscodecs/main.c
+++ b/dlls/windowscodecs/main.c
@@ -98,7 +98,7 @@ HRESULT copy_pixels(UINT bpp, const BYTE *srcbuffer,
     if (row_offset % 8 == 0)
     {
         /* everything lines up on a byte boundary */
-        UINT row;
+        INT row;
         const BYTE *src;
         BYTE *dst;
 
diff --git a/dlls/windowscodecs/metadatahandler.c b/dlls/windowscodecs/metadatahandler.c
index 6b19f842bd..7615a6dfa2 100644
--- a/dlls/windowscodecs/metadatahandler.c
+++ b/dlls/windowscodecs/metadatahandler.c
@@ -60,7 +60,7 @@ static inline MetadataHandler *impl_from_IWICPersistStream(IWICPersistStream *if
 
 static void MetadataHandler_FreeItems(MetadataHandler *This)
 {
-    int i;
+    DWORD i;
 
     for (i=0; i<This->item_count; i++)
     {
@@ -555,7 +555,7 @@ static HRESULT WINAPI MetadataHandlerEnum_Next(IWICEnumMetadataItem *iface,
     MetadataHandlerEnum *This = impl_from_IWICEnumMetadataItem(iface);
     ULONG new_index;
     HRESULT hr=S_FALSE;
-    int i;
+    ULONG i;
 
     TRACE("(%p,%i)\n", iface, celt);
 
diff --git a/dlls/windowscodecs/palette.c b/dlls/windowscodecs/palette.c
index 045f79501b..e21a0733af 100644
--- a/dlls/windowscodecs/palette.c
+++ b/dlls/windowscodecs/palette.c
@@ -592,7 +592,7 @@ static HRESULT WINAPI PaletteImpl_IsGrayscale(IWICPalette *iface, BOOL *pfIsGray
 static HRESULT WINAPI PaletteImpl_HasAlpha(IWICPalette *iface, BOOL *pfHasAlpha)
 {
     PaletteImpl *This = impl_from_IWICPalette(iface);
-    int i;
+    UINT i;
 
     TRACE("(%p,%p)\n", iface, pfHasAlpha);
 
diff --git a/dlls/windowscodecs/scaler.c b/dlls/windowscodecs/scaler.c
index 5470d2b568..03410e8c50 100644
--- a/dlls/windowscodecs/scaler.c
+++ b/dlls/windowscodecs/scaler.c
@@ -178,7 +178,7 @@ static void NearestNeighbor_CopyScanline(BitmapScaler *This,
     UINT dst_x, UINT dst_y, UINT dst_width,
     BYTE **src_data, UINT src_data_x, UINT src_data_y, BYTE *pbBuffer)
 {
-    int i;
+    UINT i;
     UINT bytesperpixel = This->bpp/8;
     UINT src_x, src_y;