diff --git a/src/evalfunc.c b/src/evalfunc.c
index e74a82a..ea633c7 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -8487,7 +8487,7 @@
 
     lnum = tv_get_lnum(argvars);		// -1 on type error
     col = (linenr_T)tv_get_number(&argvars[1]) - 1;	// -1 on type error
-    trans = (int)tv_get_number_chk(&argvars[2], &transerr);
+    trans = (int)tv_get_bool_chk(&argvars[2], &transerr);
 
     if (!transerr && lnum >= 1 && lnum <= curbuf->b_ml.ml_line_count
 	    && col >= 0 && col < (long)STRLEN(ml_get(lnum)))
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index 24377b2..ff2379a 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -1551,6 +1551,13 @@
   assert_equal(1, searchdecl('blah', true, true))
 enddef
 
+def Test_synID()
+  new
+  setline(1, "text")
+  assert_equal(0, synID(1, 1, true))
+  bwipe!
+enddef
+
 def Fibonacci(n: number): number
   if n < 2
     return n
diff --git a/src/version.c b/src/version.c
index 0cce5b2..ff291b6 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1616,
+/**/
     1615,
 /**/
     1614,