diff --git a/src/evalfunc.c b/src/evalfunc.c
index 810769a..e7683fc 100644
--- a/src/evalfunc.c
+++ b/src/evalfunc.c
@@ -7884,7 +7884,7 @@
 	if (pat == NULL)
 	    typeerr = TRUE;
 	if (argvars[2].v_type != VAR_UNKNOWN)
-	    keepempty = (int)tv_get_number_chk(&argvars[2], &typeerr);
+	    keepempty = (int)tv_get_bool_chk(&argvars[2], &typeerr);
     }
     if (pat == NULL || *pat == NUL)
 	pat = (char_u *)"[\\x01- ]\\+";
@@ -8030,7 +8030,7 @@
 	    emsg(_(e_invarg));
 	    return;
 	}
-	if (argvars[2].v_type != VAR_UNKNOWN && tv_get_number(&argvars[2]))
+	if (argvars[2].v_type != VAR_UNKNOWN && tv_get_bool(&argvars[2]))
 	    what |= STR2NR_QUOTE;
     }
 
@@ -8155,12 +8155,12 @@
 f_strchars(typval_T *argvars, typval_T *rettv)
 {
     char_u		*s = tv_get_string(&argvars[0]);
-    int			skipcc = 0;
+    int			skipcc = FALSE;
     varnumber_T		len = 0;
     int			(*func_mb_ptr2char_adv)(char_u **pp);
 
     if (argvars[1].v_type != VAR_UNKNOWN)
-	skipcc = (int)tv_get_number_chk(&argvars[1], NULL);
+	skipcc = (int)tv_get_bool(&argvars[1]);
     if (skipcc < 0 || skipcc > 1)
 	emsg(_(e_invarg));
     else
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index a277767..e315517 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -1636,6 +1636,18 @@
   endif
 enddef
 
+def Test_split()
+  split('  aa  bb  ', '\W\+', true)->assert_equal(['', 'aa', 'bb', ''])
+enddef
+
+def Test_str2nr()
+  str2nr("1'000'000", 10, true)->assert_equal(1000000)
+enddef
+
+def Test_strchars()
+  strchars("A\u20dd", true)->assert_equal(1)
+enddef
+
 def Test_synID()
   new
   setline(1, "text")
diff --git a/src/version.c b/src/version.c
index ae775d9..6a6d994 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1624,
+/**/
     1623,
 /**/
     1622,