diff --git a/src/testdir/test_let.vim b/src/testdir/test_let.vim
index 2aba1d3..e31b514 100644
--- a/src/testdir/test_let.vim
+++ b/src/testdir/test_let.vim
@@ -435,6 +435,24 @@
     call assert_report('Caught exception: ' .. v:exception)
   endtry
 
+  try
+    let v =<< trim trimm
+    trimm
+    call assert_report('No exception thrown')
+  catch /E221:/
+  catch
+    call assert_report('Caught exception: ' .. v:exception)
+  endtry
+
+  try
+    let v =<< trim trim evall
+    evall
+    call assert_report('No exception thrown')
+  catch /E221:/
+  catch
+    call assert_report('Caught exception: ' .. v:exception)
+  endtry
+
   let text =<< trim END
   func WrongSyntax()
     let v =<< that there
diff --git a/src/testdir/test_lua.vim b/src/testdir/test_lua.vim
index 5225ce8..043531a 100644
--- a/src/testdir/test_lua.vim
+++ b/src/testdir/test_lua.vim
@@ -934,7 +934,10 @@
   lua << trim eof
     vim.command('let s ..= "E"')
   eof
-  call assert_equal('ABCDE', s)
+  lua << trimm
+vim.command('let s ..= "F"')
+trimm
+  call assert_equal('ABCDEF', s)
 endfunc
 
 " Test for adding, accessing and removing global variables using the vim.g
diff --git a/src/testdir/test_perl.vim b/src/testdir/test_perl.vim
index 721179c..31329ca 100644
--- a/src/testdir/test_perl.vim
+++ b/src/testdir/test_perl.vim
@@ -359,7 +359,10 @@
   perl << trim eof
     VIM::DoCommand('let s ..= "E"')
   eof
-  call assert_equal('ABCDE', s)
+  perl << trimm
+VIM::DoCommand('let s ..= "F"')
+trimm
+  call assert_equal('ABCDEF', s)
 endfunc
 
 func Test_perl_in_sandbox()
diff --git a/src/testdir/test_python2.vim b/src/testdir/test_python2.vim
index de5f607..4ba0f8e 100644
--- a/src/testdir/test_python2.vim
+++ b/src/testdir/test_python2.vim
@@ -263,7 +263,10 @@
   python << trim eof
     s+='E'
   eof
-  call assert_equal('ABCDE', pyxeval('s'))
+python << trimm
+s+='F'
+trimm
+  call assert_equal('ABCDEF', pyxeval('s'))
 endfunc
 
 " Test for the buffer range object
diff --git a/src/testdir/test_python3.vim b/src/testdir/test_python3.vim
index 20f9dc6..c044954 100644
--- a/src/testdir/test_python3.vim
+++ b/src/testdir/test_python3.vim
@@ -467,7 +467,10 @@
   python3 << trim eof
     s+='E'
   eof
-  call assert_equal('ABCDE', pyxeval('s'))
+  python3 << trimm
+s+='F'
+trimm
+  call assert_equal('ABCDEF', pyxeval('s'))
 endfunc
 
 " Test for the buffer range object
diff --git a/src/testdir/test_pyx2.vim b/src/testdir/test_pyx2.vim
index 781bb41..68f1901 100644
--- a/src/testdir/test_pyx2.vim
+++ b/src/testdir/test_pyx2.vim
@@ -140,7 +140,10 @@
   pyx << trim eof
     result+='E'
   eof
-  call assert_equal('ABCDE', pyxeval('result'))
+  pyx << trimm
+result+='F'
+trimm
+  call assert_equal('ABCDEF', pyxeval('result'))
 endfunc
 
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/testdir/test_pyx3.vim b/src/testdir/test_pyx3.vim
index b34fdcb..b02f447 100644
--- a/src/testdir/test_pyx3.vim
+++ b/src/testdir/test_pyx3.vim
@@ -139,7 +139,10 @@
   pyx << trim eof
     result+='E'
   eof
-  call assert_equal('ABCDE', pyxeval('result'))
+  pyx << trimm
+result+='F'
+trimm
+  call assert_equal('ABCDEF', pyxeval('result'))
 endfunc
 
 " vim: shiftwidth=2 sts=2 expandtab
diff --git a/src/testdir/test_ruby.vim b/src/testdir/test_ruby.vim
index cc5f419..d4ff8e0 100644
--- a/src/testdir/test_ruby.vim
+++ b/src/testdir/test_ruby.vim
@@ -446,7 +446,10 @@
   ruby << trim eof
     Vim.command('let s ..= "E"')
   eof
-  call assert_equal('ABCDE', s)
+ruby << trimm
+Vim.command('let s ..= "F"')
+trimm
+  call assert_equal('ABCDEF', s)
 endfunc
 
 " vim: shiftwidth=2 sts=2 expandtab