diff --git a/libraries/wutdevoptab/devoptab_fs_read.c b/libraries/wutdevoptab/devoptab_fs_read.c
index fb3b2559..8047ff14 100644
--- a/libraries/wutdevoptab/devoptab_fs_read.c
+++ b/libraries/wutdevoptab/devoptab_fs_read.c
@@ -1,62 +1,64 @@
 #include "devoptab_fs.h"
 
+#include <sys/param.h>
+
 ssize_t __wut_fs_read(struct _reent *r, void *fd, char *ptr, size_t len) {
-   FSStatus status = 0;
-   FSCmdBlock cmd;
-   size_t bytesRead = 0;
-   size_t partSize[3];
-
-   __wut_fs_file_t *file = (__wut_fs_file_t *) fd;
-   __attribute__((aligned(0x40))) uint8_t alignedBuffer[0x40];
-
    if (!fd || !ptr) {
       r->_errno = EINVAL;
       return -1;
    }
 
-   FSInitCmdBlock(&cmd);
-
    // Check that the file was opened with read access
+   __wut_fs_file_t *file = (__wut_fs_file_t *) fd;
    if ((file->flags & O_ACCMODE) == O_WRONLY) {
       r->_errno = EBADF;
       return -1;
    }
 
-   partSize[0] =  (0x40 - ((uintptr_t)ptr & 0x3f)) & 0x3f;
-   if (partSize[0] > len) partSize[0] = len;
-   partSize[1] = len - partSize[0];
-   partSize[2] = partSize[1] & 0x3f;
-   partSize[1] -= partSize[2];
+   // cache-aligned, cache-line-sized
+   __attribute__((aligned(0x40))) uint8_t alignedBuffer[0x40];
 
-   if (partSize[0] + partSize[2] <= 0x40 && partSize[1] == 0) {
-      partSize[0] += partSize[2];
-      partSize[2] = 0;
-   }
+   FSCmdBlock cmd;
+   FSInitCmdBlock(&cmd);
 
-   uint8_t *tmp;
+   size_t bytesRead = 0;
+   while (bytesRead < len) {
+      // only use input buffer if cache-aligned and read size is a multiple of cache line size
+      // otherwise read into alignedBuffer
+      uint8_t *tmp = (uint8_t*) ptr;
+      size_t size = len - bytesRead;
 
-   for (int part=0; part<3; part++) {
-
-      if (!partSize[0]) continue;
-
-      if (part == 1) {
-         tmp = (uint8_t *)ptr;
+      if ((uintptr_t) ptr & 0x3F) {
+         // read partial cache-line front-end
+         tmp = alignedBuffer;
+         size = MIN(size, 0x40 - ((uintptr_t) ptr & 0x3F));
+      } else if (size < 0x40) {
+         // read partial cache-line back-end
+         tmp = alignedBuffer;
       } else {
-         tmp =  alignedBuffer;
+         // read whole cache lines
+         size &= ~0x3F;
       }
 
-      status = FSReadFile(__wut_devoptab_fs_client, &cmd, tmp, 1, partSize[part], file->fd, 0, FS_ERROR_FLAG_ALL);
+      FSStatus status = FSReadFile(__wut_devoptab_fs_client, &cmd, tmp, 1, size,
+                                   file->fd, 0, FS_ERROR_FLAG_ALL);
+
       if (status < 0) {
+         if (bytesRead != 0)
+            return bytesRead; // error after partial read
+
          r->_errno = __wut_fs_translate_error(status);
          return -1;
       }
-  
-      if (part != 1) memcpy(ptr, alignedBuffer, status);
-  
+
+      if (tmp == alignedBuffer)
+         memcpy(ptr, alignedBuffer, status);
+
       bytesRead += status;
       ptr += status;
 
-      if (status != partSize[part]) return bytesRead;
+      if (status != size)
+         return bytesRead; // partial read
    }
 
    return bytesRead;