diff --git a/renderdoc/3rdparty/tinyexr/tinyexr.h b/renderdoc/3rdparty/tinyexr/tinyexr.h
index 3637ec988..54f698a24 100644
--- a/renderdoc/3rdparty/tinyexr/tinyexr.h
+++ b/renderdoc/3rdparty/tinyexr/tinyexr.h
@@ -10495,9 +10495,9 @@ static int DecodeChunk(EXRImage *exr_image, const EXRHeader *exr_header,
         return TINYEXR_ERROR_INVALID_DATA;
       }
 
-      size_t data_size = size - (offsets[tile_idx] + sizeof(int) * 5);
+      size_t data_size = size - (size_t(offsets[tile_idx]) + sizeof(int) * 5);
       const unsigned char *data_ptr =
-          reinterpret_cast<const unsigned char *>(head + offsets[tile_idx]);
+          reinterpret_cast<const unsigned char *>(head + size_t(offsets[tile_idx]));
 
       int tile_coordinates[4];
       memcpy(tile_coordinates, data_ptr, sizeof(int) * 4);
@@ -10565,9 +10565,9 @@ static int DecodeChunk(EXRImage *exr_image, const EXRHeader *exr_header,
         // 4 byte: scan line
         // 4 byte: data size
         // ~     : pixel data(uncompressed or compressed)
-        size_t data_size = size - (offsets[y_idx] + sizeof(int) * 2);
+        size_t data_size = size - (size_t(offsets[y_idx]) + sizeof(int) * 2);
         const unsigned char *data_ptr =
-            reinterpret_cast<const unsigned char *>(head + offsets[y_idx]);
+            reinterpret_cast<const unsigned char *>(head + size_t(offsets[y_idx]));
 
         int line_no;
         memcpy(&line_no, data_ptr, sizeof(int));