diff --git a/src/testdir/dumps/Test_smooth_long_8.dump b/src/testdir/dumps/Test_smooth_long_8.dump
index c796d9a..8bdc889 100644
--- a/src/testdir/dumps/Test_smooth_long_8.dump
+++ b/src/testdir/dumps/Test_smooth_long_8.dump
@@ -3,4 +3,4 @@
 |t|s| |o|f| |t|e|x>t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o
 |f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e
 |x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w
-| @21|3|,|1|3|0| @8|B|o|t| 
+|:|s|e|t| |s|c|r|o|l@1|o| @9|3|,|1|3|0| @8|B|o|t| 
diff --git a/src/testdir/dumps/Test_smooth_long_9.dump b/src/testdir/dumps/Test_smooth_long_9.dump
index d3e6a08..8bdc889 100644
--- a/src/testdir/dumps/Test_smooth_long_9.dump
+++ b/src/testdir/dumps/Test_smooth_long_9.dump
@@ -1,6 +1,6 @@
-|<+0#4040ff13#ffffff0@2|o+0#0000000&|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o
-|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o
-|f| |t|e|x|t| |w|i>t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e
+|<+0#4040ff13#ffffff0@2|t+0#0000000&|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t
+|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o
+|t|s| |o|f| |t|e|x>t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o
+|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e
 |x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w
-|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| 
-@22|3|,|1|7|0| @8|B|o|t| 
+|:|s|e|t| |s|c|r|o|l@1|o| @9|3|,|1|3|0| @8|B|o|t| 
diff --git a/src/testdir/dumps/Test_smooth_one_long_1.dump b/src/testdir/dumps/Test_smooth_one_long_1.dump
new file mode 100644
index 0000000..82c1ea3
--- /dev/null
+++ b/src/testdir/dumps/Test_smooth_one_long_1.dump
@@ -0,0 +1,6 @@
+>w+0&#ffffff0|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h
+| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t
+|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f
+| |t|e|x|t| @34
+|~+0#4040ff13&| @38
+| +0#0000000&@21|1|,|1| @10|A|l@1| 
diff --git a/src/testdir/dumps/Test_smooth_one_long_2.dump b/src/testdir/dumps/Test_smooth_one_long_2.dump
new file mode 100644
index 0000000..46e4f59
--- /dev/null
+++ b/src/testdir/dumps/Test_smooth_one_long_2.dump
@@ -0,0 +1,6 @@
+|<+0#4040ff13#ffffff0@2|t+0#0000000&|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t
+>s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f| |t|e|x|t| |w|i|t|h| |l|o|t|s| |o|f
+| |t|e|x|t| @34
+|~+0#4040ff13&| @38
+|~| @38
+| +0#0000000&@21|1|,|8|1| @9|A|l@1| 
diff --git a/src/testdir/test_scroll_opt.vim b/src/testdir/test_scroll_opt.vim
index 5bea957..48c81f2 100644
--- a/src/testdir/test_scroll_opt.vim
+++ b/src/testdir/test_scroll_opt.vim
@@ -248,5 +248,26 @@
   call StopVimInTerminal(buf)
 endfunc
 
+func Test_smoothscroll_one_long_line()
+  CheckScreendump
+
+  let lines =<< trim END
+      vim9script
+      setline(1, 'with lots of text '->repeat(7))
+      set smoothscroll scrolloff=0
+  END
+  call writefile(lines, 'XSmoothOneLong', 'D')
+  let buf = RunVimInTerminal('-S XSmoothOneLong', #{rows: 6, cols: 40})
+  call VerifyScreenDump(buf, 'Test_smooth_one_long_1', {})
+  
+  call term_sendkeys(buf, "\<C-E>")
+  call VerifyScreenDump(buf, 'Test_smooth_one_long_2', {})
+
+  call term_sendkeys(buf, "0")
+  call VerifyScreenDump(buf, 'Test_smooth_one_long_1', {})
+
+  call StopVimInTerminal(buf)
+endfunc
+
 
 " vim: shiftwidth=2 sts=2 expandtab