diff --git a/src/testdir/test_substitute.vim b/src/testdir/test_substitute.vim
index 4c99f81..0c36748 100644
--- a/src/testdir/test_substitute.vim
+++ b/src/testdir/test_substitute.vim
@@ -1,6 +1,7 @@
 " Tests for multi-line regexps with ":s".
 
 source shared.vim
+source check.vim
 
 func Test_multiline_subst()
   enew!
@@ -453,6 +454,13 @@
    call assert_fails("call substitute('123', '2', Replacer, 'g')", 'E118:')
 endfunc
 
+func Test_substitute_float()
+  CheckFeature float
+
+  call assert_equal('number 1.23', substitute('number ', '$', { -> 1.23 }, ''))
+  vim9 assert_equal('number 1.23', substitute('number ', '$', () => 1.23, ''))
+endfunc
+
 " Tests for *sub-replace-special* and *sub-replace-expression* on :substitute.
 
 " Execute a list of :substitute command tests