diff --git a/src/groupchat.c b/src/groupchat.c
index e624569..33dd56b 100644
--- a/src/groupchat.c
+++ b/src/groupchat.c
@@ -308,6 +308,22 @@ static void groupchat_onKey(ToxWindow *self, Tox *m, wint_t key)
         }
     }
 
+    else if (key == '\t') {    /* TAB key: completes peer name */
+        if (ctx->len >= 2) {
+            int diff = complete_line(ctx->line, &ctx->pos, &ctx->len, groupchats[self->num].peer_names, 
+                                     groupchats[self->num].num_peers, TOX_MAX_NAME_LENGTH);
+
+            if (diff != -1 && (ctx->len < (x2 * (CHATBOX_HEIGHT - 1)-1))) {
+                if (x + diff > x2 - 1) {
+                    int ofst = (x + diff - 1) - (x2 - 1);
+                    wmove(self->window, y+1, ofst);
+                } else {
+                    wmove(self->window, y, x+diff);
+                }
+            }
+        }
+    }
+
     /* Scroll peerlist up and down one position if list overflows window */
     else if (key == KEY_NPAGE) {
         int L = y2 - CHATBOX_HEIGHT - SDBAR_OFST;
diff --git a/src/misc_tools.c b/src/misc_tools.c
index 22ab0bf..587c918 100644
--- a/src/misc_tools.c
+++ b/src/misc_tools.c
@@ -57,7 +57,36 @@ int string_is_empty(char *string)
     return string[0] == '\0';
 }
 
-/* convert wide characters to null terminated string */
+/* convert a multibyte string to a wide character string (must provide buffer) */
+int char_to_wcs_buf(wchar_t *buf, const uint8_t *string, size_t n)
+{
+    size_t len = mbstowcs(NULL, string, 0) + 1;
+
+    if (n < len)
+        return -1;
+
+    if ((len = mbstowcs(buf, string, n)) == (size_t) -1)
+        return -1;
+
+    return len;
+}
+
+/* converts wide character string into a multibyte string.
+   Same thing as wcs_to_char() but caller must provide its own buffer */
+int wcs_to_char_buf(uint8_t *buf, const wchar_t *string, size_t n)
+{
+    size_t len = wcstombs(NULL, string, 0) + 1;
+
+    if (n < len)
+        return -1;
+
+    if ((len = wcstombs(buf, string, n)) == (size_t) -1)
+        return -1;
+
+    return len;
+}
+
+/* convert wide characters to multibyte string */
 uint8_t *wcs_to_char(wchar_t *string)
 {
     uint8_t *ret = NULL;
@@ -66,8 +95,10 @@ uint8_t *wcs_to_char(wchar_t *string)
     if (len != (size_t) -1) {
         ret = malloc(++len);
 
-        if (ret != NULL)
-            wcstombs(ret, string, len);
+        if (ret != NULL) {
+            if (wcstombs(ret, string, len) == (size_t) -1)
+                return NULL;
+        }
     } else {
         ret = malloc(2);
 
@@ -86,7 +117,7 @@ uint8_t *wcs_to_char(wchar_t *string)
     return ret;
 }
 
-/* convert a wide char to null terminated string */
+/* convert a wide char to multibyte string */
 char *wc_to_char(wchar_t ch)
 {
     static char ret[MB_LEN_MAX + 1];
@@ -251,3 +282,67 @@ void reset_buf(wchar_t *buf, size_t *pos, size_t *len)
     *pos = 0;
     *len = 0;
 }
+
+/* looks for the first instance in list that begins with the last entered word in buf according to pos, 
+   then fills buf with the complete word. e.g. "Hello jo" would complete the buffer 
+   with "Hello john". It shouldn't matter where pos is within buf.
+
+   list is a pointer to the list of strings being compared, n_items is the number of items
+   in the list, and size is the size of each item in the list. 
+
+   Returns the difference between the old len and new len of buf */
+int complete_line(wchar_t *buf, size_t *pos, size_t *len, const uint8_t *list, int n_items, int size)
+{
+    if (*pos <= 0 || *len < 2 || *len > MAX_STR_SIZE)
+        return -1;
+
+    uint8_t ubuf[MAX_STR_SIZE];
+
+    if (wcs_to_char_buf(ubuf, buf, MAX_STR_SIZE) == -1)
+        return -1;
+
+    /* isolate substring from space behind pos to pos */
+    uint8_t tmp[MAX_STR_SIZE];
+    snprintf(tmp, sizeof(tmp), "%s", ubuf);
+    tmp[*pos] = '\0';
+    uint8_t *sub = strrchr(tmp, ' ');
+
+    if (!sub++)
+        sub = tmp;
+
+    const uint8_t *match;
+    int i;
+
+    /* look for a match in list */
+    for (i = 0; i < n_items; ++i) {
+        if (match = strstr(&list[i*size], sub))
+            break;
+    }
+
+    if (!match)
+        return -1;
+
+    /* put match in correct spot in buf */
+    int s_len = strlen(sub);
+    int m_len = strlen(match);
+    int strt = *pos - s_len;
+
+    uint8_t tmpend[MAX_STR_SIZE];
+    strcpy(tmpend, &ubuf[*pos]);
+    strcpy(&ubuf[strt], match);
+    strcpy(&ubuf[strt+m_len], tmpend);
+
+    /* convert to widechar and copy back to original buf */
+    wchar_t newbuf[MAX_STR_SIZE];
+
+    if (char_to_wcs_buf(newbuf, ubuf, MAX_STR_SIZE) == -1)
+        return -1;
+
+    int diff = m_len - s_len;
+    *len += diff;
+    *pos += diff;
+
+    wmemcpy(buf, newbuf, MAX_STR_SIZE);
+
+    return diff;
+}
diff --git a/src/misc_tools.h b/src/misc_tools.h
index 10df073..6963a94 100644
--- a/src/misc_tools.h
+++ b/src/misc_tools.h
@@ -16,10 +16,17 @@ void print_time(WINDOW *window);
 /* Returns 1 if the string is empty, 0 otherwise */
 int string_is_empty(char *string);
 
-/* convert wide characters to null terminated string */
+/* convert a multibyte string to a wide character string (must provide buffer) */
+int char_to_wcs_buf(wchar_t *buf, const uint8_t *string, size_t n);
+
+/* converts wide character string into a multibyte string.
+   Same thing as wcs_to_char() but caller must provide its own buffer */
+int wcs_to_char_buf(uint8_t *buf, const wchar_t *string, size_t n);
+
+/* convert wide characters to multibyte string string */
 uint8_t *wcs_to_char(wchar_t *string);
 
-/* convert a wide char to null terminated string */
+/* convert a wide char to multibyte string string */
 char *wc_to_char(wchar_t ch);
 
 /* Returns true if connection has timed out, false otherwise */
@@ -58,3 +65,12 @@ void kill_buf(wchar_t *buf, size_t *pos, size_t *len);
 
 /* nulls buf and sets pos and len to 0 */
 void reset_buf(wchar_t *buf, size_t *pos, size_t *len);
+
+/* looks for the first instance in list that begins with the last entered word in buf, 
+   then completes the word. e.g. "Hello jo" would complete the buffer with "Hello john".
+
+   list is a pointer to the list of strings being compared, n_items is the number of items
+   in the list, and size is the size of each item in the list.
+
+   Returns the difference between the old len and new len of buf */
+int complete_line(wchar_t *buf, size_t *pos, size_t *len, const uint8_t *list, int n_items, int size);
\ No newline at end of file
diff --git a/src/windows.c b/src/windows.c
index 13c154d..dcd7755 100644
--- a/src/windows.c
+++ b/src/windows.c
@@ -221,7 +221,7 @@ void set_next_window(int ch)
     ToxWindow *inf = active_window;
 
     while (true) {
-        if (ch == '\t' || ch == T_KEY_NEXT) {
+        if (ch == T_KEY_NEXT) {
             if (++active_window > end)
                 active_window = windows;
         } else if (--active_window < windows)
@@ -348,7 +348,7 @@ void draw_active_window(Tox *m)
     ch = getch();
 #endif
 
-    if (ch == '\t' || ch == KEY_BTAB || ch == T_KEY_NEXT || ch == T_KEY_PREV)
+    if (ch == T_KEY_NEXT || ch == T_KEY_PREV)
         set_next_window((int) ch);
     else if (ch != ERR)
         a->onKey(a, m, ch);