diff --git a/source/blender/imbuf/intern/openexr/openexr_api.cpp b/source/blender/imbuf/intern/openexr/openexr_api.cpp
index fefec3e22f3..55b28be39c5 100644
--- a/source/blender/imbuf/intern/openexr/openexr_api.cpp
+++ b/source/blender/imbuf/intern/openexr/openexr_api.cpp
@@ -502,8 +502,8 @@ static bool imb_save_openexr_half(ImBuf *ibuf, const char *filepath, const int f
     OutputFile file(*file_stream, header);
 
     /* we store first everything in half array */
-    std::vector<RGBAZ> pixels(height * width);
-    RGBAZ *to = pixels.data();
+    std::unique_ptr<RGBAZ[]> pixels = std::unique_ptr<RGBAZ[]>(new RGBAZ[int64_t(height) * width]);
+    RGBAZ *to = pixels.get();
     int xstride = sizeof(RGBAZ);
     int ystride = xstride * width;
 
@@ -518,7 +518,7 @@ static bool imb_save_openexr_half(ImBuf *ibuf, const char *filepath, const int f
       float *from;
 
       for (int i = ibuf->y - 1; i >= 0; i--) {
-        from = ibuf->float_buffer.data + channels * i * width;
+        from = ibuf->float_buffer.data + int64_t(channels) * i * width;
 
         for (int j = ibuf->x; j > 0; j--) {
           to->r = float_to_half_safe(from[0]);
@@ -534,7 +534,7 @@ static bool imb_save_openexr_half(ImBuf *ibuf, const char *filepath, const int f
       uchar *from;
 
       for (int i = ibuf->y - 1; i >= 0; i--) {
-        from = ibuf->byte_buffer.data + 4 * i * width;
+        from = ibuf->byte_buffer.data + int64_t(4) * i * width;
 
         for (int j = ibuf->x; j > 0; j--) {
           to->r = srgb_to_linearrgb(float(from[0]) / 255.0f);
@@ -608,7 +608,7 @@ static bool imb_save_openexr_float(ImBuf *ibuf, const char *filepath, const int
 
     /* Last scan-line, stride negative. */
     float *rect[4] = {nullptr, nullptr, nullptr, nullptr};
-    rect[0] = ibuf->float_buffer.data + channels * (height - 1) * width;
+    rect[0] = ibuf->float_buffer.data + int64_t(channels) * (height - 1) * width;
     rect[1] = (channels >= 2) ? rect[0] + 1 : rect[0];
     rect[2] = (channels >= 3) ? rect[0] + 2 : rect[0];
     rect[3] = (channels >= 4) ?