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