diff --git a/src/evalbuffer.c b/src/evalbuffer.c
index 3004415..4ca68c8 100644
--- a/src/evalbuffer.c
+++ b/src/evalbuffer.c
@@ -391,7 +391,7 @@
     // new buffer.
     if (buf == NULL
 	    && argvars[1].v_type != VAR_UNKNOWN
-	    && tv_get_number_chk(&argvars[1], &error) != 0
+	    && tv_get_bool_chk(&argvars[1], &error) != 0
 	    && !error
 	    && (name = tv_get_string_chk(&argvars[0])) != NULL
 	    && !error)
diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index f79c2e0..ad3268a 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -1327,6 +1327,10 @@
 def Test_bufnr()
   let buf = bufnr()
   assert_equal(buf, bufnr('%'))
+
+  buf = bufnr('Xdummy', true)
+  assert_notequal(-1, buf)
+  exe 'bwipe! ' .. buf
 enddef
 
 def Test_col()
diff --git a/src/version.c b/src/version.c
index 26a30c1..53a3ed0 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1590,
+/**/
     1589,
 /**/
     1588,