diff --git a/runtime/syntax/generator/vim.vim.base b/runtime/syntax/generator/vim.vim.base
index 42c93dc..bd597e9 100644
--- a/runtime/syntax/generator/vim.vim.base
+++ b/runtime/syntax/generator/vim.vim.base
@@ -369,7 +369,9 @@
 
 " Lower Priority Comments: after some vim commands... {{{2
 " =======================
-syn region	vimCommentString	contained oneline start='\S\s\+"'ms=e end='"'
+if get(g:, "vimsyn_comment_strings", 1)
+  syn region	vimCommentString	contained oneline start='\S\s\+"'ms=e end='"'
+endif
 
 if s:vim9script
   syn match	vimComment	excludenl +\s"[^\-:.%#=*].*$+lc=1	contains=@vimCommentGroup,vimCommentString contained
diff --git a/runtime/syntax/testdir/dumps/vim9_ex_comment_strings_00.dump b/runtime/syntax/testdir/dumps/vim9_ex_comment_strings_00.dump
new file mode 100644
index 0000000..0236684
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim9_ex_comment_strings_00.dump
@@ -0,0 +1,20 @@
+>v+0#af5f00255#ffffff0|i|m|9|s|c|r|i|p|t| +0#0000000&@64
+@75
+|#+0#0000e05&| |V|i|m| |c|o|m@1|e|n|t| |s|t|r|i|n|g|s| +0#0000000&@53
+|#+0#0000e05&| |V|I|M|_|T|E|S|T|_|S|E|T|U|P| |l|e|t| |g|:|v|i|m|s|y|n|_|c|o|m@1|e|n|t|_|s|t|r|i|n|g|s| |=| |v|:|t|r|u|e| +0#0000000&@20
+@75
+|#+0#0000e05&| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@55
+@75
+|f+0#af5f00255&|u|n|c|t|i|o|n| +0#0000000&|F|o@1|(+0#e000e06&|)| +0#0000000&@60
+| +0#0000e05&@1|"| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+|e+0#af5f00255&|n|d|f|u|n|c|t|i|o|n| +0#0000000&@63
+@75
+|d+0#af5f00255&|e|f| +0#0000000&|B|a|r|(+0#e000e06&|)| +0#0000000&@65
+| +0#0000e05&@1|#| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@68
+@75
+|c+0#af5f00255&|o|m@1|a|n|d| +0#0000000&|F|o@1| |{+0#e000e06&| +0#0000000&@61
+| +0#0000e05&@1|#| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+|}+0#e000e06&| +0#0000000&@73
+@75
+@57|1|,|1| @10|T|o|p| 
diff --git a/runtime/syntax/testdir/dumps/vim9_ex_comment_strings_01.dump b/runtime/syntax/testdir/dumps/vim9_ex_comment_strings_01.dump
new file mode 100644
index 0000000..1fd26e6
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim9_ex_comment_strings_01.dump
@@ -0,0 +1,20 @@
+|e+0#af5f00255#ffffff0|n|d@1|e|f| +0#0000000&@68
+@75
+|c+0#af5f00255&|o|m@1|a|n|d| +0#0000000&|F|o@1| |{+0#e000e06&| +0#0000000&@61
+| +0#0000e05&@1|#| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+|}+0#e000e06&| +0#0000000&@73
+> @74
+|a+0#af5f00255&|u|t|o|c|m|d| +0#0000000&|B+0#00e0003&|u|f|N|e|w|F|i|l|e| +0#0000000&|*| |{+0#e000e06&| +0#0000000&@52
+| +0#0000e05&@1|#| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+|}+0#e000e06&| +0#0000000&@73
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|1|9|,|0|-|1| @7|B|o|t| 
diff --git a/runtime/syntax/testdir/dumps/vim9_ex_comment_strings_99.dump b/runtime/syntax/testdir/dumps/vim9_ex_comment_strings_99.dump
new file mode 100644
index 0000000..1f495da
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim9_ex_comment_strings_99.dump
@@ -0,0 +1,20 @@
+|#+0#0000e05#ffffff0| |V|I|M|_|T|E|S|T|_|S|E|T|U|P| |l|e|t| |g|:|v|i|m|s|y|n|_|c|o|m@1|e|n|t|_|s|t|r|i|n|g|s| |=| |v|:|t|r|u|e| +0#0000000&@20
+@75
+|#+0#0000e05&| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@55
+@75
+|f+0#af5f00255&|u|n|c|t|i|o|n| +0#0000000&|F|o@1|(+0#e000e06&|)| +0#0000000&@60
+| +0#0000e05&@1|"| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+|e+0#af5f00255&|n|d|f|u|n|c|t|i|o|n| +0#0000000&@63
+@75
+|d+0#af5f00255&|e|f| +0#0000000&|B|a|r|(+0#e000e06&|)| +0#0000000&@65
+| +0#0000e05&@1|#| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@68
+@75
+|c+0#af5f00255&|o|m@1|a|n|d| +0#0000000&|F|o@1| |{+0#e000e06&| +0#0000000&@61
+| +0#0000e05&@1|#| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+|}+0#e000e06&| +0#0000000&@73
+@75
+|a+0#af5f00255&|u|t|o|c|m|d| +0#0000000&|B+0#00e0003&|u|f|N|e|w|F|i|l|e| +0#0000000&|*| |{+0#e000e06&| +0#0000000&@52
+| +0#0000e05&@1|#| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+>}+0#e000e06&| +0#0000000&@73
+@57|2@1|,|1| @9|B|o|t| 
diff --git a/runtime/syntax/testdir/dumps/vim9_ex_no_comment_strings_00.dump b/runtime/syntax/testdir/dumps/vim9_ex_no_comment_strings_00.dump
new file mode 100644
index 0000000..cc6ffe5
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim9_ex_no_comment_strings_00.dump
@@ -0,0 +1,20 @@
+>v+0#af5f00255#ffffff0|i|m|9|s|c|r|i|p|t| +0#0000000&@64
+@75
+|#+0#0000e05&| |V|i|m| |c|o|m@1|e|n|t| |s|t|r|i|n|g|s| +0#0000000&@53
+|#+0#0000e05&| |V|I|M|_|T|E|S|T|_|S|E|T|U|P| |l|e|t| |g|:|v|i|m|s|y|n|_|c|o|m@1|e|n|t|_|s|t|r|i|n|g|s| |=| |v|:|f|a|l|s|e| +0#0000000&@19
+@75
+|#+0#0000e05&| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@55
+@75
+|f+0#af5f00255&|u|n|c|t|i|o|n| +0#0000000&|F|o@1|(+0#e000e06&|)| +0#0000000&@60
+| +0#0000e05&@1|"| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+|e+0#af5f00255&|n|d|f|u|n|c|t|i|o|n| +0#0000000&@63
+@75
+|d+0#af5f00255&|e|f| +0#0000000&|B|a|r|(+0#e000e06&|)| +0#0000000&@65
+| +0#0000e05&@1|#| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@68
+@75
+|c+0#af5f00255&|o|m@1|a|n|d| +0#0000000&|F|o@1| |{+0#e000e06&| +0#0000000&@61
+| +0#0000e05&@1|#| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+|}+0#e000e06&| +0#0000000&@73
+@75
+@57|1|,|1| @10|T|o|p| 
diff --git a/runtime/syntax/testdir/dumps/vim9_ex_no_comment_strings_01.dump b/runtime/syntax/testdir/dumps/vim9_ex_no_comment_strings_01.dump
new file mode 100644
index 0000000..bde4dbc
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim9_ex_no_comment_strings_01.dump
@@ -0,0 +1,20 @@
+|e+0#af5f00255#ffffff0|n|d@1|e|f| +0#0000000&@68
+@75
+|c+0#af5f00255&|o|m@1|a|n|d| +0#0000000&|F|o@1| |{+0#e000e06&| +0#0000000&@61
+| +0#0000e05&@1|#| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+|}+0#e000e06&| +0#0000000&@73
+> @74
+|a+0#af5f00255&|u|t|o|c|m|d| +0#0000000&|B+0#00e0003&|u|f|N|e|w|F|i|l|e| +0#0000000&|*| |{+0#e000e06&| +0#0000000&@52
+| +0#0000e05&@1|#| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+|}+0#e000e06&| +0#0000000&@73
+|~+0#4040ff13&| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+| +0#0000000&@56|1|9|,|0|-|1| @7|B|o|t| 
diff --git a/runtime/syntax/testdir/dumps/vim9_ex_no_comment_strings_99.dump b/runtime/syntax/testdir/dumps/vim9_ex_no_comment_strings_99.dump
new file mode 100644
index 0000000..8445c5b
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim9_ex_no_comment_strings_99.dump
@@ -0,0 +1,20 @@
+|#+0#0000e05#ffffff0| |V|I|M|_|T|E|S|T|_|S|E|T|U|P| |l|e|t| |g|:|v|i|m|s|y|n|_|c|o|m@1|e|n|t|_|s|t|r|i|n|g|s| |=| |v|:|f|a|l|s|e| +0#0000000&@19
+@75
+|#+0#0000e05&| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@55
+@75
+|f+0#af5f00255&|u|n|c|t|i|o|n| +0#0000000&|F|o@1|(+0#e000e06&|)| +0#0000000&@60
+| +0#0000e05&@1|"| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+|e+0#af5f00255&|n|d|f|u|n|c|t|i|o|n| +0#0000000&@63
+@75
+|d+0#af5f00255&|e|f| +0#0000000&|B|a|r|(+0#e000e06&|)| +0#0000000&@65
+| +0#0000e05&@1|#| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@68
+@75
+|c+0#af5f00255&|o|m@1|a|n|d| +0#0000000&|F|o@1| |{+0#e000e06&| +0#0000000&@61
+| +0#0000e05&@1|#| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+|}+0#e000e06&| +0#0000000&@73
+@75
+|a+0#af5f00255&|u|t|o|c|m|d| +0#0000000&|B+0#00e0003&|u|f|N|e|w|F|i|l|e| +0#0000000&|*| |{+0#e000e06&| +0#0000000&@52
+| +0#0000e05&@1|#| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+>}+0#e000e06&| +0#0000000&@73
+@57|2@1|,|1| @9|B|o|t| 
diff --git a/runtime/syntax/testdir/dumps/vim_ex_comment_strings_00.dump b/runtime/syntax/testdir/dumps/vim_ex_comment_strings_00.dump
new file mode 100644
index 0000000..6aef5b6
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim_ex_comment_strings_00.dump
@@ -0,0 +1,20 @@
+>"+0#0000e05#ffffff0| |V|i|m| |c|o|m@1|e|n|t| |s|t|r|i|n|g|s| +0#0000000&@53
+|"+0#0000e05&| |V|I|M|_|T|E|S|T|_|S|E|T|U|P| |l|e|t| |g|:|v|i|m|s|y|n|_|c|o|m@1|e|n|t|_|s|t|r|i|n|g|s| |=| |v|:|t|r|u|e| +0#0000000&@20
+@75
+|"+0#0000e05&| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@55
+@75
+|f+0#af5f00255&|u|n|c|t|i|o|n| +0#0000000&|F|o@1|(+0#e000e06&|)| +0#0000000&@60
+| +0#0000e05&@1|"| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+|e+0#af5f00255&|n|d|f|u|n|c|t|i|o|n| +0#0000000&@63
+@75
+|d+0#af5f00255&|e|f| +0#0000000&|B|a|r|(+0#e000e06&|)| +0#0000000&@65
+| +0#0000e05&@1|#| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@68
+@75
+|c+0#af5f00255&|o|m@1|a|n|d| +0#0000000&|F|o@1| |{+0#e000e06&| +0#0000000&@61
+| +0#0000e05&@1|#| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+|}+0#e000e06&| +0#0000000&@73
+@75
+|a+0#af5f00255&|u|t|o|c|m|d| +0#0000000&|B+0#00e0003&|u|f|N|e|w|F|i|l|e| +0#0000000&|*| |{+0#e000e06&| +0#0000000&@52
+| +0#0000e05&@1|#| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+@57|1|,|1| @10|T|o|p| 
diff --git a/runtime/syntax/testdir/dumps/vim_ex_comment_strings_99.dump b/runtime/syntax/testdir/dumps/vim_ex_comment_strings_99.dump
new file mode 100644
index 0000000..13671f6
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim_ex_comment_strings_99.dump
@@ -0,0 +1,20 @@
+|"+0#0000e05#ffffff0| |V|I|M|_|T|E|S|T|_|S|E|T|U|P| |l|e|t| |g|:|v|i|m|s|y|n|_|c|o|m@1|e|n|t|_|s|t|r|i|n|g|s| |=| |v|:|t|r|u|e| +0#0000000&@20
+@75
+|"+0#0000e05&| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@55
+@75
+|f+0#af5f00255&|u|n|c|t|i|o|n| +0#0000000&|F|o@1|(+0#e000e06&|)| +0#0000000&@60
+| +0#0000e05&@1|"| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+|e+0#af5f00255&|n|d|f|u|n|c|t|i|o|n| +0#0000000&@63
+@75
+|d+0#af5f00255&|e|f| +0#0000000&|B|a|r|(+0#e000e06&|)| +0#0000000&@65
+| +0#0000e05&@1|#| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@68
+@75
+|c+0#af5f00255&|o|m@1|a|n|d| +0#0000000&|F|o@1| |{+0#e000e06&| +0#0000000&@61
+| +0#0000e05&@1|#| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+|}+0#e000e06&| +0#0000000&@73
+@75
+|a+0#af5f00255&|u|t|o|c|m|d| +0#0000000&|B+0#00e0003&|u|f|N|e|w|F|i|l|e| +0#0000000&|*| |{+0#e000e06&| +0#0000000&@52
+| +0#0000e05&@1|#| |p|r|e| |"+0#e000002&|s|t|r|i|n|g|"| +0#0000e05&|p|o|s|t| +0#0000000&@53
+>}+0#e000e06&| +0#0000000&@73
+@57|2|0|,|1| @9|B|o|t| 
diff --git a/runtime/syntax/testdir/dumps/vim_ex_no_comment_strings_00.dump b/runtime/syntax/testdir/dumps/vim_ex_no_comment_strings_00.dump
new file mode 100644
index 0000000..fc55c39
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim_ex_no_comment_strings_00.dump
@@ -0,0 +1,20 @@
+>"+0#0000e05#ffffff0| |V|i|m| |c|o|m@1|e|n|t| |s|t|r|i|n|g|s| +0#0000000&@53
+|"+0#0000e05&| |V|I|M|_|T|E|S|T|_|S|E|T|U|P| |l|e|t| |g|:|v|i|m|s|y|n|_|c|o|m@1|e|n|t|_|s|t|r|i|n|g|s| |=| |v|:|f|a|l|s|e| +0#0000000&@19
+@75
+|"+0#0000e05&| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@55
+@75
+|f+0#af5f00255&|u|n|c|t|i|o|n| +0#0000000&|F|o@1|(+0#e000e06&|)| +0#0000000&@60
+| +0#0000e05&@1|"| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+|e+0#af5f00255&|n|d|f|u|n|c|t|i|o|n| +0#0000000&@63
+@75
+|d+0#af5f00255&|e|f| +0#0000000&|B|a|r|(+0#e000e06&|)| +0#0000000&@65
+| +0#0000e05&@1|#| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@68
+@75
+|c+0#af5f00255&|o|m@1|a|n|d| +0#0000000&|F|o@1| |{+0#e000e06&| +0#0000000&@61
+| +0#0000e05&@1|#| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+|}+0#e000e06&| +0#0000000&@73
+@75
+|a+0#af5f00255&|u|t|o|c|m|d| +0#0000000&|B+0#00e0003&|u|f|N|e|w|F|i|l|e| +0#0000000&|*| |{+0#e000e06&| +0#0000000&@52
+| +0#0000e05&@1|#| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+@57|1|,|1| @10|T|o|p| 
diff --git a/runtime/syntax/testdir/dumps/vim_ex_no_comment_strings_99.dump b/runtime/syntax/testdir/dumps/vim_ex_no_comment_strings_99.dump
new file mode 100644
index 0000000..7bff27b
--- /dev/null
+++ b/runtime/syntax/testdir/dumps/vim_ex_no_comment_strings_99.dump
@@ -0,0 +1,20 @@
+|"+0#0000e05#ffffff0| |V|I|M|_|T|E|S|T|_|S|E|T|U|P| |l|e|t| |g|:|v|i|m|s|y|n|_|c|o|m@1|e|n|t|_|s|t|r|i|n|g|s| |=| |v|:|f|a|l|s|e| +0#0000000&@19
+@75
+|"+0#0000e05&| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@55
+@75
+|f+0#af5f00255&|u|n|c|t|i|o|n| +0#0000000&|F|o@1|(+0#e000e06&|)| +0#0000000&@60
+| +0#0000e05&@1|"| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+|e+0#af5f00255&|n|d|f|u|n|c|t|i|o|n| +0#0000000&@63
+@75
+|d+0#af5f00255&|e|f| +0#0000000&|B|a|r|(+0#e000e06&|)| +0#0000000&@65
+| +0#0000e05&@1|#| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+|e+0#af5f00255&|n|d@1|e|f| +0#0000000&@68
+@75
+|c+0#af5f00255&|o|m@1|a|n|d| +0#0000000&|F|o@1| |{+0#e000e06&| +0#0000000&@61
+| +0#0000e05&@1|#| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+|}+0#e000e06&| +0#0000000&@73
+@75
+|a+0#af5f00255&|u|t|o|c|m|d| +0#0000000&|B+0#00e0003&|u|f|N|e|w|F|i|l|e| +0#0000000&|*| |{+0#e000e06&| +0#0000000&@52
+| +0#0000e05&@1|#| |p|r|e| |"|s|t|r|i|n|g|"| |p|o|s|t| +0#0000000&@53
+>}+0#e000e06&| +0#0000000&@73
+@57|2|0|,|1| @9|B|o|t| 
diff --git a/runtime/syntax/testdir/input/vim9_ex_comment_strings.vim b/runtime/syntax/testdir/input/vim9_ex_comment_strings.vim
new file mode 100644
index 0000000..fd02c1a
--- /dev/null
+++ b/runtime/syntax/testdir/input/vim9_ex_comment_strings.vim
@@ -0,0 +1,22 @@
+vim9script
+
+# Vim comment strings
+# VIM_TEST_SETUP let g:vimsyn_comment_strings = v:true
+
+# pre "string" post
+
+function Foo()
+  " pre "string" post
+endfunction
+
+def Bar()
+  # pre "string" post
+enddef
+
+command Foo {
+  # pre "string" post
+}
+
+autocmd BufNewFile * {
+  # pre "string" post
+}
diff --git a/runtime/syntax/testdir/input/vim9_ex_no_comment_strings.vim b/runtime/syntax/testdir/input/vim9_ex_no_comment_strings.vim
new file mode 100644
index 0000000..dcea14d
--- /dev/null
+++ b/runtime/syntax/testdir/input/vim9_ex_no_comment_strings.vim
@@ -0,0 +1,22 @@
+vim9script
+
+# Vim comment strings
+# VIM_TEST_SETUP let g:vimsyn_comment_strings = v:false
+
+# pre "string" post
+
+function Foo()
+  " pre "string" post
+endfunction
+
+def Bar()
+  # pre "string" post
+enddef
+
+command Foo {
+  # pre "string" post
+}
+
+autocmd BufNewFile * {
+  # pre "string" post
+}
diff --git a/runtime/syntax/testdir/input/vim_ex_comment_strings.vim b/runtime/syntax/testdir/input/vim_ex_comment_strings.vim
new file mode 100644
index 0000000..4214d6b
--- /dev/null
+++ b/runtime/syntax/testdir/input/vim_ex_comment_strings.vim
@@ -0,0 +1,20 @@
+" Vim comment strings
+" VIM_TEST_SETUP let g:vimsyn_comment_strings = v:true
+
+" pre "string" post
+
+function Foo()
+  " pre "string" post
+endfunction
+
+def Bar()
+  # pre "string" post
+enddef
+
+command Foo {
+  # pre "string" post
+}
+
+autocmd BufNewFile * {
+  # pre "string" post
+}
diff --git a/runtime/syntax/testdir/input/vim_ex_no_comment_strings.vim b/runtime/syntax/testdir/input/vim_ex_no_comment_strings.vim
new file mode 100644
index 0000000..d9b53b3
--- /dev/null
+++ b/runtime/syntax/testdir/input/vim_ex_no_comment_strings.vim
@@ -0,0 +1,20 @@
+" Vim comment strings
+" VIM_TEST_SETUP let g:vimsyn_comment_strings = v:false
+
+" pre "string" post
+
+function Foo()
+  " pre "string" post
+endfunction
+
+def Bar()
+  # pre "string" post
+enddef
+
+command Foo {
+  # pre "string" post
+}
+
+autocmd BufNewFile * {
+  # pre "string" post
+}
diff --git a/runtime/syntax/vim.vim b/runtime/syntax/vim.vim
index 5ad4d00..7208661 100644
--- a/runtime/syntax/vim.vim
+++ b/runtime/syntax/vim.vim
@@ -408,7 +408,9 @@
 
 " Lower Priority Comments: after some vim commands... {{{2
 " =======================
-syn region	vimCommentString	contained oneline start='\S\s\+"'ms=e end='"'
+if get(g:, "vimsyn_comment_strings", 1)
+  syn region	vimCommentString	contained oneline start='\S\s\+"'ms=e end='"'
+endif
 
 if s:vim9script
   syn match	vimComment	excludenl +\s"[^\-:.%#=*].*$+lc=1	contains=@vimCommentGroup,vimCommentString contained