diff --git a/apps/plugins/viewer.c b/apps/plugins/viewer.c
index 2ed0cd8..de97737 100644
--- a/apps/plugins/viewer.c
+++ b/apps/plugins/viewer.c
@@ -548,6 +548,11 @@ struct viewport vp;
 struct bookmark_info bookmarks[MAX_BOOKMARKS];
 static int bookmark_count;
 
+/* UTF-8 BOM */
+#define BOM "\xef\xbb\xbf"
+#define BOM_SIZE 3
+
+static bool is_bom = false;
 
 static int glyph_width(int ch)
 {
@@ -830,7 +835,7 @@ static unsigned char* find_prev_line(const unsigned char* cur_line)
         /* (else return NULL and read previous block) */
 
     /* Wrap downwards until too far, then use the one before. */
-    while (p < cur_line && p != NULL) {
+    while (p != NULL && p < cur_line) {
         prev_line = p;
         p = find_next_line(prev_line, NULL);
     }
@@ -841,15 +846,34 @@ static unsigned char* find_prev_line(const unsigned char* cur_line)
     return (unsigned char*) prev_line;
 }
 
+static void check_bom(void)
+{
+    unsigned char bom[BOM_SIZE];
+    off_t orig = rb->lseek(fd, 0, SEEK_CUR);
+
+    is_bom = false;
+
+    rb->lseek(fd, 0, SEEK_SET);
+
+    if (rb->read(fd, bom, BOM_SIZE) == BOM_SIZE)
+        is_bom = !memcmp(bom, BOM, BOM_SIZE);
+
+    rb->lseek(fd, orig, SEEK_SET);
+}
+
 static void fill_buffer(long pos, unsigned char* buf, unsigned size)
 {
     /* Read from file and preprocess the data */
     /* To minimize disk access, always read on sector boundaries */
     unsigned numread, i;
     bool found_CR = false;
+    off_t offset = rb->lseek(fd, pos, SEEK_SET);
+
+    if (offset == 0 && prefs.encoding == UTF_8 && is_bom)
+        rb->lseek(fd, BOM_SIZE, SEEK_SET);
 
-    rb->lseek(fd, pos, SEEK_SET);
     numread = rb->read(fd, buf, size);
+    buf[numread] = 0;
     rb->button_clear_queue(); /* clear button queue */
 
     for(i = 0; i < numread; i++) {
@@ -1099,7 +1123,11 @@ static void viewer_draw(int col)
 
         get_next_line_position(&line_begin, &line_end, &line_is_short);
         if (line_end == NULL)
-            break;
+        {
+           if (BUFFER_OOB(line_begin))
+                break;
+           line_end = buffer_end + 1;
+        }
 
         line_len = line_end - line_begin;
 
@@ -1461,16 +1489,25 @@ static bool viewer_init(void)
     if (fd==-1)
         return false;
 
-    file_size = rb->filesize(fd);
-    if (file_size==-1)
-        return false;
-
     /* Init mac_text value used in processing buffer */
     mac_text = false;
 
     return true;
 }
 
+/* When a file is UTF-8 file with BOM, if prefs.encoding is UTF-8,
+ * then file size decreases only BOM_SIZE.
+ */
+static void get_filesize(void)
+{
+    file_size = rb->filesize(fd);
+    if (file_size == -1)
+        return;
+
+    if (prefs.encoding == UTF_8 && is_bom)
+        file_size -= BOM_SIZE;
+}
+
 static int bm_comp(const void *a, const void *b)
 {
     struct bookmark_info *pa;
@@ -1850,6 +1887,9 @@ read_end:
 
     viewer_remove_last_read_bookmark();
 
+    check_bom();
+    get_filesize();
+
     buffer_end = BUFFER_END();  /* Update whenever file_pos changes */
 
     if (BUFFER_OOB(screen_top_ptr))
@@ -2094,10 +2134,16 @@ static void calc_page(void)
     {
         if (bookmarks[i].flag & BOOKMARK_LAST)
         {
+            int screen_pos;
+            int screen_top;
+
+            screen_pos = bookmarks[i].file_position;
+            screen_top = screen_pos % buffer_size;
+            file_pos = screen_pos - screen_top;
+            screen_top_ptr = buffer + screen_top;
+
             cpage = bookmarks[i].page;
             cline = bookmarks[i].line;
-            file_pos = bookmarks[i].file_position;
-            screen_top_ptr = buffer;
             bookmarks[i].flag ^= BOOKMARK_LAST;
             buffer_end = BUFFER_END();
 
@@ -2134,6 +2180,8 @@ static bool encoding_setting(void)
 {
     static struct opt_items names[NUM_CODEPAGES];
     int idx;
+    bool res;
+    enum codepages oldenc = prefs.encoding;
 
     for (idx = 0; idx < NUM_CODEPAGES; idx++)
     {
@@ -2141,8 +2189,21 @@ static bool encoding_setting(void)
         names[idx].voice_id = -1;
     }
 
-    return rb->set_option("Encoding", &prefs.encoding, INT, names,
+    res = rb->set_option("Encoding", &prefs.encoding, INT, names,
                           sizeof(names) / sizeof(names[0]), NULL);
+
+    /* When prefs.encoding changes into UTF-8 or changes from UTF-8,
+     * filesize (file_size) might change.
+     * In addition, if prefs.encoding is UTF-8, then BOM does not read.
+     */
+    if (oldenc != prefs.encoding && (oldenc == UTF_8 || prefs.encoding == UTF_8))
+    {
+        check_bom();
+        get_filesize();
+        fill_buffer(file_pos, buffer, buffer_size);
+    }
+
+    return res;
 }
 
 static bool word_wrap_setting(void)