diff --git a/src/gmio_stl/internal/stlb_byte_swap.c b/src/gmio_stl/internal/stlb_byte_swap.c
index d65220c..99622ab 100644
--- a/src/gmio_stl/internal/stlb_byte_swap.c
+++ b/src/gmio_stl/internal/stlb_byte_swap.c
@@ -21,9 +21,10 @@ void gmio_stl_triangle_bswap(gmio_stl_triangle_t* triangle)
 {
     int i;
     uint32_t* uintcoord_ptr = (uint32_t*)&(triangle->normal.x);
+    const uint16_t attr_byte_count = triangle->attribute_byte_count;
 
     for (i = 0; i < 12; ++i)
         *(uintcoord_ptr + i) = gmio_uint32_bswap(*(uintcoord_ptr + i));
-    if (triangle->attribute_byte_count != 0)
-        triangle->attribute_byte_count = gmio_uint16_bswap(triangle->attribute_byte_count);
+    if (attr_byte_count != 0)
+        triangle->attribute_byte_count = gmio_uint16_bswap(attr_byte_count);
 }
diff --git a/src/gmio_stl/stlb_read.c b/src/gmio_stl/stlb_read.c
index 0384bdb..71aa529 100644
--- a/src/gmio_stl/stlb_read.c
+++ b/src/gmio_stl/stlb_read.c
@@ -78,6 +78,7 @@ int gmio_stlb_read(
                     trsf->buffer.size / GMIO_STLB_TRIANGLE_RAWSIZE)
               : 0;
     /* Variables */
+    void* buffer_ptr = trsf != NULL ? trsf->buffer.ptr : NULL;
     gmio_stlb_readwrite_helper_t rparams = {0};
     uint8_t header_data[GMIO_STLB_HEADER_SIZE];
     uint32_t total_facet_count = 0; /* Facet count, as declared in the stream */
@@ -99,13 +100,13 @@ int gmio_stlb_read(
     }
 
     /* Read facet count */
-    if (gmio_stream_read(&trsf->stream, trsf->buffer.ptr, sizeof(uint32_t), 1)
+    if (gmio_stream_read(&trsf->stream, buffer_ptr, sizeof(uint32_t), 1)
             != 1)
     {
         return GMIO_STLB_READ_FACET_COUNT_ERROR;
     }
 
-    memcpy(&total_facet_count, trsf->buffer.ptr, sizeof(uint32_t));
+    memcpy(&total_facet_count, buffer_ptr, sizeof(uint32_t));
     if (byte_order != GMIO_HOST_ENDIANNESS)
         total_facet_count = gmio_uint32_bswap(total_facet_count);
 
@@ -126,7 +127,7 @@ int gmio_stlb_read(
                 gmio_size_to_uint32(
                     gmio_stream_read(
                         &trsf->stream,
-                        trsf->buffer.ptr,
+                        buffer_ptr,
                         GMIO_STLB_TRIANGLE_RAWSIZE,
                         max_facet_count_per_read));
         if (gmio_stream_error(&trsf->stream) != 0)
@@ -137,7 +138,7 @@ int gmio_stlb_read(
             break; /* Exit if no facet to read */
 
         if (gmio_no_error(error)) {
-            gmio_stlb_read_facets(creator, trsf->buffer.ptr, &rparams);
+            gmio_stlb_read_facets(creator, buffer_ptr, &rparams);
             rparams.i_facet_offset += rparams.facet_count;
             if (gmio_transfer_is_stop_requested(trsf))
                 error = GMIO_TRANSFER_STOPPED_ERROR;
diff --git a/src/gmio_stl/stlb_write.c b/src/gmio_stl/stlb_write.c
index 7b95c59..a418617 100644
--- a/src/gmio_stl/stlb_write.c
+++ b/src/gmio_stl/stlb_write.c
@@ -80,6 +80,7 @@ int gmio_stlb_write(
     const uint32_t facet_count =
             mesh != NULL ? mesh->triangle_count : 0;
     /* Variables */
+    void* buffer_ptr = trsf != NULL ? trsf->buffer.ptr : NULL;
     gmio_stlb_readwrite_helper_t wparams = {0};
     uint32_t i_facet = 0;
     int error = GMIO_NO_ERROR;
@@ -99,8 +100,8 @@ int gmio_stlb_write(
     /* Write header */
     if (header_data == NULL) {
         /* Use buffer to store an empty header (filled with zeroes) */
-        memset(trsf->buffer.ptr, 0, GMIO_STLB_HEADER_SIZE);
-        header_data = (const uint8_t*)trsf->buffer.ptr;
+        memset(buffer_ptr, 0, GMIO_STLB_HEADER_SIZE);
+        header_data = (const uint8_t*)buffer_ptr;
     }
     if (gmio_stream_write(&trsf->stream, header_data, GMIO_STLB_HEADER_SIZE, 1)
             != 1)
@@ -110,14 +111,11 @@ int gmio_stlb_write(
 
     /* Write facet count */
     if (byte_order == GMIO_LITTLE_ENDIAN)
-        gmio_encode_uint32_le(facet_count, trsf->buffer.ptr);
+        gmio_encode_uint32_le(facet_count, buffer_ptr);
     else
-        gmio_encode_uint32_be(facet_count, trsf->buffer.ptr);
-    if (gmio_stream_write(&trsf->stream, trsf->buffer.ptr, sizeof(uint32_t), 1)
-            != 1)
-    {
+        gmio_encode_uint32_be(facet_count, buffer_ptr);
+    if (gmio_stream_write(&trsf->stream, buffer_ptr, sizeof(uint32_t), 1) != 1)
         return GMIO_STREAM_ERROR;
-    }
 
     /* Write triangles */
     for (i_facet = 0;
@@ -130,13 +128,13 @@ int gmio_stlb_write(
         wparams.facet_count = GMIO_MIN(wparams.facet_count,
                                        facet_count - wparams.i_facet_offset);
 
-        gmio_stlb_write_facets(mesh, trsf->buffer.ptr, &wparams);
+        gmio_stlb_write_facets(mesh, buffer_ptr, &wparams);
         wparams.i_facet_offset += wparams.facet_count;
 
         /* Write buffer to stream */
         if (gmio_stream_write(
                     &trsf->stream,
-                    trsf->buffer.ptr,
+                    buffer_ptr,
                     GMIO_STLB_TRIANGLE_RAWSIZE,
                     wparams.facet_count)
                 != wparams.facet_count)