diff --git a/dlls/windowscodecs/tests/info.c b/dlls/windowscodecs/tests/info.c
index 339555f23fe..31416f3d8f1 100644
--- a/dlls/windowscodecs/tests/info.c
+++ b/dlls/windowscodecs/tests/info.c
@@ -114,7 +114,7 @@ static void test_decoder_info(void)
     IWICBitmapDecoderInfo *decoder_info, *decoder_info2;
     IWICComponentInfo *info;
     HRESULT hr;
-    ULONG len;
+    UINT len;
     WCHAR value[256];
     CLSID clsid;
     GUID pixelformats[32];
@@ -292,7 +292,7 @@ static void test_pixelformat_info(void)
     IWICPixelFormatInfo *pixelformat_info;
     IWICPixelFormatInfo2 *pixelformat_info2;
     HRESULT hr;
-    ULONG len, known_len;
+    UINT len, known_len;
     WCHAR value[256];
     GUID guid;
     WICComponentType componenttype;
@@ -499,7 +499,8 @@ static void test_reader_info(void)
     HRESULT hr;
     CLSID clsid;
     GUID container_formats[10];
-    UINT count, size, tid;
+    UINT count, size;
+    DWORD tid;
     HANDLE thread;
     WICMetadataPattern *patterns;
 
diff --git a/dlls/windowscodecs/tests/metadata.c b/dlls/windowscodecs/tests/metadata.c
index bec8bb08c76..8eaf22a300c 100644
--- a/dlls/windowscodecs/tests/metadata.c
+++ b/dlls/windowscodecs/tests/metadata.c
@@ -321,7 +321,8 @@ static void test_metadata_tEXt(void)
     IWICMetadataReader *reader;
     IWICEnumMetadataItem *enumerator;
     PROPVARIANT schema, id, value;
-    ULONG items_returned, count;
+    ULONG items_returned;
+    UINT count;
     GUID format;
 
     PropVariantInit(&schema);
@@ -438,7 +439,7 @@ static void test_metadata_gAMA(void)
     HRESULT hr;
     IWICMetadataReader *reader;
     PROPVARIANT schema, id, value;
-    ULONG count;
+    UINT count;
     GUID format;
     static const WCHAR ImageGamma[] = {'I','m','a','g','e','G','a','m','m','a',0};
 
@@ -483,7 +484,7 @@ static void test_metadata_cHRM(void)
     HRESULT hr;
     IWICMetadataReader *reader;
     PROPVARIANT schema, id, value;
-    ULONG count;
+    UINT count;
     GUID format;
     int i;
     static const WCHAR expected_names[8][12] = {
@@ -799,7 +800,7 @@ static void test_metadata_IFD(void)
     IWICMetadataReader *reader;
     IWICMetadataBlockReader *blockreader;
     PROPVARIANT schema, id, value;
-    ULONG count;
+    UINT count;
     GUID format;
     char *IFD_data_swapped;
 #ifdef WORDS_BIGENDIAN
diff --git a/dlls/windowscodecs/tests/palette.c b/dlls/windowscodecs/tests/palette.c
index 583fa66c80e..d07b936ca9e 100644
--- a/dlls/windowscodecs/tests/palette.c
+++ b/dlls/windowscodecs/tests/palette.c
@@ -205,7 +205,7 @@ static void test_custom_palette(void)
     }
 }
 
-static void generate_gray16_palette(DWORD *entries, UINT count)
+static void generate_gray16_palette(WICColor *entries, UINT count)
 {
     UINT i;
 
@@ -218,7 +218,7 @@ static void generate_gray16_palette(DWORD *entries, UINT count)
     }
 }
 
-static void generate_gray256_palette(DWORD *entries, UINT count)
+static void generate_gray256_palette(WICColor *entries, UINT count)
 {
     UINT i;
 
@@ -231,7 +231,7 @@ static void generate_gray256_palette(DWORD *entries, UINT count)
     }
 }
 
-static void generate_halftone8_palette(DWORD *entries, UINT count, BOOL add_transparent)
+static void generate_halftone8_palette(WICColor *entries, UINT count, BOOL add_transparent)
 {
     UINT i;
 
@@ -260,7 +260,7 @@ static void generate_halftone8_palette(DWORD *entries, UINT count, BOOL add_tran
         entries[i] = 0;
 }
 
-static void generate_halftone27_palette(DWORD *entries, UINT count, BOOL add_transparent)
+static void generate_halftone27_palette(WICColor *entries, UINT count, BOOL add_transparent)
 {
     static const BYTE halftone_values[4] = { 0x00,0x80,0xff };
     UINT i;
@@ -283,7 +283,7 @@ static void generate_halftone27_palette(DWORD *entries, UINT count, BOOL add_tra
         entries[i] = 0;
 }
 
-static void generate_halftone64_palette(DWORD *entries, UINT count, BOOL add_transparent)
+static void generate_halftone64_palette(WICColor *entries, UINT count, BOOL add_transparent)
 {
     static const BYTE halftone_values[4] = { 0x00,0x55,0xaa,0xff };
     UINT i;
@@ -313,7 +313,7 @@ static void generate_halftone64_palette(DWORD *entries, UINT count, BOOL add_tra
         entries[i] = 0;
 }
 
-static void generate_halftone125_palette(DWORD *entries, UINT count, BOOL add_transparent)
+static void generate_halftone125_palette(WICColor *entries, UINT count, BOOL add_transparent)
 {
     static const BYTE halftone_values[5] = { 0x00, 0x40, 0x80, 0xbf, 0xff };
     UINT i;
@@ -336,7 +336,7 @@ static void generate_halftone125_palette(DWORD *entries, UINT count, BOOL add_tr
         entries[i] = 0;
 }
 
-static void generate_halftone216_palette(DWORD *entries, UINT count, BOOL add_transparent)
+static void generate_halftone216_palette(WICColor *entries, UINT count, BOOL add_transparent)
 {
     static const BYTE halftone_values[6] = { 0x00,0x33,0x66,0x99,0xcc,0xff };
     UINT i;
@@ -366,7 +366,7 @@ static void generate_halftone216_palette(DWORD *entries, UINT count, BOOL add_tr
         entries[i] = 0;
 }
 
-static void generate_halftone252_palette(DWORD *entries, UINT count, BOOL add_transparent)
+static void generate_halftone252_palette(WICColor *entries, UINT count, BOOL add_transparent)
 {
     static const BYTE halftone_values_rb[6] = { 0x00,0x33,0x66,0x99,0xcc,0xff };
     static const BYTE halftone_values_g[7] = { 0x00,0x2b,0x55,0x80,0xaa,0xd5,0xff };
@@ -389,7 +389,7 @@ static void generate_halftone252_palette(DWORD *entries, UINT count, BOOL add_tr
         entries[i] = 0;
 }
 
-static void generate_halftone256_palette(DWORD *entries, UINT count, BOOL add_transparent)
+static void generate_halftone256_palette(WICColor *entries, UINT count, BOOL add_transparent)
 {
     static const BYTE halftone_values_b[4] = { 0x00,0x55,0xaa,0xff };
     static const BYTE halftone_values_gr[8] = { 0x00,0x24,0x49,0x6d,0x92,0xb6,0xdb,0xff };