diff --git a/src/emu/video.c b/src/emu/video.c
index 0d27b56dcf9..a86704da38a 100644
--- a/src/emu/video.c
+++ b/src/emu/video.c
@@ -2073,13 +2073,15 @@ static void update_refresh_speed(running_machine *machine)
 				}
 
 			/* compute a target speed as an integral percentage */
-			target_speed = floor(minrefresh * 100.0 / ATTOSECONDS_TO_HZ(min_frame_period));
+			/* note that we lop 0.25Hz off of the minrefresh when doing the computation to allow for
+			   the fact that most refresh rates are not accurate to 10 digits... */
+			target_speed = floor((minrefresh - 0.25f) * 100.0 / ATTOSECONDS_TO_HZ(min_frame_period));
 			target_speed = MIN(target_speed, original_speed);
 
 			/* if we changed, log that verbosely */
 			if (target_speed != global.speed)
 			{
-				mame_printf_verbose("Adjusting target speed to %d%%\n", target_speed);
+				mame_printf_verbose("Adjusting target speed to %d%% (hw=%.2fHz, game=%.2fHz, adjusted=%.2fHz)\n", target_speed, minrefresh, ATTOSECONDS_TO_HZ(min_frame_period), ATTOSECONDS_TO_HZ(min_frame_period * 100 / target_speed));
 				global.speed = target_speed;
 			}
 		}