diff --git a/src/libvterm/src/mouse.c b/src/libvterm/src/mouse.c
index 4e36313..ed60b01 100644
--- a/src/libvterm/src/mouse.c
+++ b/src/libvterm/src/mouse.c
@@ -83,7 +83,7 @@
       state->mouse_buttons &= ~(1 << (button-1));
   }
 
-  /* Most of the time we don't get button releases from 4/5 */
+  /* Most of the time we don't get button releases from 4/5/6/7 */
   if(state->mouse_buttons == old_buttons && button < 4)
     return;
   if (!(state->mouse_flags & MOUSE_WANT_CLICK))
@@ -92,7 +92,7 @@
   if(button < 4) {
     output_mouse(state, button-1, pressed, mod, state->mouse_col, state->mouse_row);
   }
-  else if(button < 6) {
+  else if(button < 8) {
     output_mouse(state, button-4 + 0x40, pressed, mod, state->mouse_col, state->mouse_row);
   }
 }
diff --git a/src/mouse.c b/src/mouse.c
index 5abb942..143bcf2 100644
--- a/src/mouse.c
+++ b/src/mouse.c
@@ -2119,6 +2119,7 @@
 # endif
     int		mouse_code = 0;	    // init for GCC
     int		is_click, is_drag;
+    int		is_release, release_is_ambiguous;
     int		wheel_code = 0;
     int		current_button;
     static int	held_button = MOUSE_RELEASE;
@@ -2133,7 +2134,7 @@
     long	timediff;		// elapsed time in msec
 # endif
 
-    is_click = is_drag = FALSE;
+    is_click = is_drag = is_release = release_is_ambiguous = FALSE;
 
 # if !defined(UNIX) || defined(FEAT_MOUSE_XTERM) || defined(FEAT_GUI) \
     || defined(FEAT_MOUSE_GPM) || defined(FEAT_SYSMOUSE)
@@ -2256,9 +2257,6 @@
 		|| key_name[0] == KS_SGR_MOUSE_RELEASE)
 	    mouse_code += 32;
 
-	if (key_name[0] == KS_SGR_MOUSE_RELEASE)
-	    mouse_code |= MOUSE_RELEASE;
-
 	mouse_col = getdigits(&p) - 1;
 	if (*p++ != ';')
 	    return -1;
@@ -2270,6 +2268,19 @@
 	*modifiers = 0;
     }
 
+    if (key_name[0] == KS_SGR_MOUSE
+	    || key_name[0] == KS_SGR_MOUSE_RELEASE)
+    {
+	if (key_name[0] == KS_SGR_MOUSE_RELEASE)
+	    is_release = TRUE;
+    }
+    else
+    {
+	release_is_ambiguous = TRUE;
+	if ((mouse_code & MOUSE_RELEASE) == MOUSE_RELEASE)
+	    is_release = TRUE;
+    }
+
     if (key_name[0] == KS_MOUSE
 #  ifdef FEAT_MOUSE_GPM
 	    || key_name[0] == KS_GPM_MOUSE
@@ -2331,7 +2342,7 @@
 #   ifdef FEAT_XCLIPBOARD
 	else if (!(mouse_code & MOUSE_DRAG & ~MOUSE_CLICK_MASK))
 	{
-	    if ((mouse_code & MOUSE_RELEASE) == MOUSE_RELEASE)
+	    if (is_release)
 		stop_xterm_trace();
 	    else
 		start_xterm_trace(mouse_code);
@@ -2469,12 +2480,13 @@
 		if (button & 16) mouse_code |= MOUSE_CTRL;
 		break;
 	    case 'u': // Button Up
+		is_release = TRUE;
 		if (button & 1)
-		    mouse_code |= MOUSE_LEFT | MOUSE_RELEASE;
+		    mouse_code |= MOUSE_LEFT;
 		if (button & 2)
-		    mouse_code |= MOUSE_MIDDLE | MOUSE_RELEASE;
+		    mouse_code |= MOUSE_MIDDLE;
 		if (button & 4)
-		    mouse_code |= MOUSE_RIGHT | MOUSE_RELEASE;
+		    mouse_code |= MOUSE_RIGHT;
 		if (button & 8)
 		    mouse_code |= MOUSE_SHIFT;
 		if (button & 16)
@@ -2598,17 +2610,20 @@
 	    case  2: mouse_code = MOUSE_LEFT;
 		     WantQueryMouse = TRUE;
 		     break;
-	    case  3: mouse_code = MOUSE_RELEASE | MOUSE_LEFT;
+	    case  3: mouse_code = MOUSE_LEFT;
+		     is_release = TRUE;
 		     break;
 	    case  4: mouse_code = MOUSE_MIDDLE;
 		     WantQueryMouse = TRUE;
 		     break;
-	    case  5: mouse_code = MOUSE_RELEASE | MOUSE_MIDDLE;
+	    case  5: mouse_code = MOUSE_MIDDLE;
+		     is_release = TRUE;
 		     break;
 	    case  6: mouse_code = MOUSE_RIGHT;
 		     WantQueryMouse = TRUE;
 		     break;
-	    case  7: mouse_code = MOUSE_RELEASE | MOUSE_RIGHT;
+	    case  7: mouse_code = MOUSE_RIGHT;
+		     is_release = TRUE;
 		     break;
 	    case  8: return -1; // fourth button down
 	    case  9: return -1; // fourth button up
@@ -2661,7 +2676,7 @@
 		break;
 
 	    case 32: // Release
-		mouse_code |= MOUSE_RELEASE;
+		is_release = TRUE;
 		break;
 
 	    case 33: // Drag
@@ -2682,6 +2697,9 @@
 
     // Interpret the mouse code
     current_button = (mouse_code & MOUSE_CLICK_MASK);
+    if (is_release)
+	current_button |= MOUSE_RELEASE;
+
     if (current_button == MOUSE_RELEASE
 # ifdef FEAT_MOUSE_XTERM
 	    && wheel_code == 0
@@ -2786,15 +2804,22 @@
     // Work out our pseudo mouse event. Note that MOUSE_RELEASE gets
     // added, then it's not mouse up/down.
     key_name[0] = KS_EXTRA;
-    if (wheel_code != 0
-	    && (wheel_code & MOUSE_RELEASE) != MOUSE_RELEASE)
+    if (wheel_code != 0 && (!is_release || release_is_ambiguous))
     {
 	if (wheel_code & MOUSE_CTRL)
 	    *modifiers |= MOD_MASK_CTRL;
 	if (wheel_code & MOUSE_ALT)
 	    *modifiers |= MOD_MASK_ALT;
-	key_name[1] = (wheel_code & 1)
-	    ? (int)KE_MOUSEUP : (int)KE_MOUSEDOWN;
+
+	if (wheel_code & 1 && wheel_code & 2)
+	    key_name[1] = (int)KE_MOUSELEFT;
+	else if (wheel_code & 2)
+	    key_name[1] = (int)KE_MOUSERIGHT;
+	else if (wheel_code & 1)
+	    key_name[1] = (int)KE_MOUSEUP;
+	else
+	    key_name[1] = (int)KE_MOUSEDOWN;
+
 	held_button = MOUSE_RELEASE;
     }
     else
diff --git a/src/terminal.c b/src/terminal.c
index 5424574..bd5fd41 100644
--- a/src/terminal.c
+++ b/src/terminal.c
@@ -1389,8 +1389,8 @@
 
 	case K_MOUSEUP:		other = term_send_mouse(vterm, 5, 1); break;
 	case K_MOUSEDOWN:	other = term_send_mouse(vterm, 4, 1); break;
-	case K_MOUSELEFT:	/* TODO */ return 0;
-	case K_MOUSERIGHT:	/* TODO */ return 0;
+	case K_MOUSELEFT:	other = term_send_mouse(vterm, 7, 1); break;
+	case K_MOUSERIGHT:	other = term_send_mouse(vterm, 6, 1); break;
 
 	case K_LEFTMOUSE:
 	case K_LEFTMOUSE_NM:
@@ -2474,6 +2474,8 @@
 	restore_cursor = TRUE;
 
 	raw_c = term_vgetc();
+if (raw_c > 0)
+    ch_log(NULL, "terminal_loop() got %d", raw_c);
 	if (!term_use_loop_check(TRUE) || in_terminal_loop != curbuf->b_term)
 	{
 	    // Job finished while waiting for a character.  Push back the
diff --git a/src/testdir/mouse.vim b/src/testdir/mouse.vim
index a28a439..5eab1de 100644
--- a/src/testdir/mouse.vim
+++ b/src/testdir/mouse.vim
@@ -169,4 +169,20 @@
   call feedkeys(MouseWheelDownCode(a:row, a:col), 'Lx!')
 endfunc
 
+func MouseWheelLeftCode(row, col)
+  return TerminalEscapeCode(0x42, a:row, a:col, 'M')
+endfunc
+
+func MouseWheelLeft(row, col)
+  call feedkeys(MouseWheelLeftCode(a:row, a:col), 'Lx!')
+endfunc
+
+func MouseWheelRightCode(row, col)
+  return TerminalEscapeCode(0x43, a:row, a:col, 'M')
+endfunc
+
+func MouseWheelRight(row, col)
+  call feedkeys(MouseWheelRightCode(a:row, a:col), 'Lx!')
+endfunc
+
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/testdir/test_termcodes.vim b/src/testdir/test_termcodes.vim
index 27c2a18..a267696 100644
--- a/src/testdir/test_termcodes.vim
+++ b/src/testdir/test_termcodes.vim
@@ -194,9 +194,10 @@
   new
   let save_mouse = &mouse
   let save_term = &term
+  let save_wrap = &wrap
   let save_ttymouse = &ttymouse
-  set mouse=a term=xterm
-  call setline(1, range(1, 100))
+  set mouse=a term=xterm nowrap
+  call setline(1, range(100000000000000, 100000000000100))
 
   for ttymouse_val in g:Ttymouse_values
     let msg = 'ttymouse=' .. ttymouse_val
@@ -220,10 +221,31 @@
     call MouseWheelUp(1, 1)
     call assert_equal(1, line('w0'), msg)
     call assert_equal([0, 7, 1, 0], getpos('.'), msg)
+
+    if has('gui')
+      " Horizontal wheel scrolling currently only works when vim is
+      " compiled with gui enabled.
+      call MouseWheelRight(1, 1)
+      call assert_equal(7, 1 + virtcol(".") - wincol(), msg)
+      call assert_equal([0, 7, 7, 0], getpos('.'), msg)
+
+      call MouseWheelRight(1, 1)
+      call assert_equal(13, 1 + virtcol(".") - wincol(), msg)
+      call assert_equal([0, 7, 13, 0], getpos('.'), msg)
+
+      call MouseWheelLeft(1, 1)
+      call assert_equal(7, 1 + virtcol(".") - wincol(), msg)
+      call assert_equal([0, 7, 13, 0], getpos('.'), msg)
+
+      call MouseWheelLeft(1, 1)
+      call assert_equal(1, 1 + virtcol(".") - wincol(), msg)
+      call assert_equal([0, 7, 13, 0], getpos('.'), msg)
+    endif
   endfor
 
   let &mouse = save_mouse
   let &term = save_term
+  let &wrap = save_wrap
   let &ttymouse = save_ttymouse
   bwipe!
 endfunc
diff --git a/src/version.c b/src/version.c
index 97c3c4c..2691996 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1108,
+/**/
     1107,
 /**/
     1106,