diff --git a/Machines/Atari/ST/Video.cpp b/Machines/Atari/ST/Video.cpp
index e8ae8cfe0..064fa98b2 100644
--- a/Machines/Atari/ST/Video.cpp
+++ b/Machines/Atari/ST/Video.cpp
@@ -438,8 +438,9 @@ HalfCycles Video::get_next_sequence_point() {
 	if(x_ < line_length_.hsync_start + hsync_delay_period) {
 		event_time = std::min(line_length_.hsync_start + hsync_delay_period, event_time);
 	}
-	/* Hereby assumed: hsync end will be communicated at end of line: */
-//	static_assert(line_length_.hsync_end == hsync_delay_period);
+	if(x_ < line_length_.hsync_end + hsync_delay_period) {
+		event_time = std::min(line_length_.hsync_end + hsync_delay_period, event_time);
+	}
 
 	// Also factor in the line length latching time.
 	if(x_ < line_length_latch_position) {
diff --git a/Machines/Atari/ST/Video.hpp b/Machines/Atari/ST/Video.hpp
index 719e4f4b3..299f3941c 100644
--- a/Machines/Atari/ST/Video.hpp
+++ b/Machines/Atari/ST/Video.hpp
@@ -23,8 +23,8 @@ namespace ST {
 
 struct LineLength {
 	int length = 1024;
-	int hsync_start;
-	int hsync_end;
+	int hsync_start = 1024;
+	int hsync_end = 1024;
 };
 
 /*!