diff --git a/Doc/make.bat b/Doc/make.bat
index cff85ceabae..d28dae78e86 100644
--- a/Doc/make.bat
+++ b/Doc/make.bat
@@ -131,6 +131,9 @@ if exist ..\Misc\NEWS (
 if NOT "%PAPER%" == "" (
     set SPHINXOPTS=-D latex_elements.papersize=%PAPER% %SPHINXOPTS%
 )
+if "%1" EQU "htmlhelp" (
+    set SPHINXOPTS=-D html_theme_options.body_max_width=none %SPHINXOPTS%
+)
 cmd /S /C "%SPHINXBUILD% %SPHINXOPTS% -b%1 -dbuild\doctrees . "%BUILDDIR%\%1" %2 %3 %4 %5 %6 %7 %8 %9"
 
 if "%1" EQU "htmlhelp" (
diff --git a/Misc/NEWS.d/next/Windows/2018-07-02-14-19-32.bpo-34006.7SgBT_.rst b/Misc/NEWS.d/next/Windows/2018-07-02-14-19-32.bpo-34006.7SgBT_.rst
new file mode 100644
index 00000000000..f21e51646f1
--- /dev/null
+++ b/Misc/NEWS.d/next/Windows/2018-07-02-14-19-32.bpo-34006.7SgBT_.rst
@@ -0,0 +1,3 @@
+Revert line length limit for Windows help docs. The line-length limit is not
+needed because the pages appear in a separate app rather than on a browser
+tab.  It can also interact badly with the DPI setting.