diff --git a/runtime/syntax/generator/vim.vim.base b/runtime/syntax/generator/vim.vim.base
index 5fc0d08..fe87119 100644
--- a/runtime/syntax/generator/vim.vim.base
+++ b/runtime/syntax/generator/vim.vim.base
@@ -467,11 +467,13 @@
 " GEN_SYN_VIM: vimCommand mapclear, START_STR='syn keyword vimMap', END_STR='skipwhite nextgroup=vimMapMod'
 syn keyword	vimMap mapc[lear]	skipwhite nextgroup=vimMapBang,vimMapMod
 " GEN_SYN_VIM: vimCommand unmap, START_STR='syn keyword vimUnmap', END_STR='skipwhite nextgroup=vimMapBang,vimMapMod,vimMapLhs'
-syn match	vimMapLhs	contained	"\S\+"			contains=vimNotation,vimCtrlChar skipwhite nextgroup=vimMapRhs
-syn match	vimMapBang	contained	"\a\@1<=!"			skipwhite nextgroup=vimMapMod,vimMapLhs
+syn match	vimMapLhs	contained	"\%(.\|\S\)\+"		contains=vimCtrlChar,vimNotation skipwhite        nextgroup=vimMapRhs
+syn match	vimMapLhs	contained	"\%(.\|\S\)\+\ze\s*$"	contains=vimCtrlChar,vimNotation skipwhite skipnl nextgroup=vimMapRhsContinue
+syn match	vimMapBang	contained	"\a\@1<=!"		skipwhite nextgroup=vimMapMod,vimMapLhs
 syn match	vimMapMod	contained	"\%#=1\c<\(buffer\|expr\|\(local\)\=leader\|nowait\|plug\|script\|sid\|unique\|silent\)\+>" contains=vimMapModKey,vimMapModErr skipwhite nextgroup=vimMapMod,vimMapLhs
-syn match	vimMapRhs	contained	".*" contains=vimNotation,vimCtrlChar	skipnl nextgroup=vimMapRhsExtend
-syn match	vimMapRhsExtend	contained	"^\s*\\.*$"			contains=vimContinue
+syn region	vimMapRhs	contained	start="\S" 	        skip=+\\|\|\@1<=|\|\n\s*\\\|\n\s*"\\ + end="|" end="$" contains=@vimContinue,vimCtrlChar,vimNotation skipnl nextgroup=vimMapRhsContinue
+" assume a continuation comment introduces the RHS
+syn region	vimMapRhsContinue	contained	start=+^\s*\%(\\\|"\\ \)+ skip=+\\|\|\@1<=|\|\n\s*\\\|\n\s*"\\ + end="|" end="$" contains=@vimContinue,vimCtrlChar,vimNotation
 syn case ignore
 syn keyword	vimMapModKey	contained	buffer	expr	leader	localleader	nowait	plug	script	sid	silent	unique
 syn case match
@@ -1137,4 +1139,4 @@
 delc VimFoldt
 let &cpo = s:keepcpo
 unlet s:keepcpo
-" vim:ts=18  fdm=marker
+" vim:ts=18 fdm=marker ft=vim