--- a/gbversion.h.qmake.in
+++ b/gbversion.h.qmake.in
@@ -14,5 +14,5 @@
 #else
 #define VERSION \"$${GB.MAJOR}.$${GB.MINOR}.$${GB.MICRO}$${GB.PACKAGE_RELEASE}\"
 constexpr char kVersionSHA[] = \"$${GB.SHA}\";
-#define WEB_DOC_DIR \"https://www.gpsbabel.org/htmldoc-$${DOCVERSION}\"
+#define WEB_DOC_DIR \"file:///usr/share/doc/gpsbabel\"
 #endif
--- a/gui/mainwindow.cc
+++ b/gui/mainwindow.cc
@@ -1156,7 +1156,7 @@ void MainWindow::preferencesActionX()
 //------------------------------------------------------------------------
 void MainWindow::helpActionX()
 {
-  ShowHelp("index.html");
+  ShowHelp("gpsbabel.html");
 }
 //------------------------------------------------------------------------
 void MainWindow::filtersClicked()
--- a/testo.d/serialization.test
+++ b/testo.d/serialization.test
@@ -7,7 +7,7 @@
 # the GUI and the document.
 # We do a compare_nole as specific whitespace is part of deserialization.
 gpsbabel -^3 > ${TMPDIR}/format3.txt
-sed 's,https://www.gpsbabel.org/htmldoc-.[^/]*/,https://www.gpsbabel.org/WEB_DOC_DIR/,' ${TMPDIR}/format3.txt >${TMPDIR}/format3.fiddled.txt
+sed 's,file:///usr/share/doc/gpsbabel/,https://www.gpsbabel.org/WEB_DOC_DIR/,' ${TMPDIR}/format3.txt >${TMPDIR}/format3.fiddled.txt
 compare_nole ${REFERENCE}/format3.txt ${TMPDIR}/format3.fiddled.txt
 gpsbabel -^2 > ${TMPDIR}/format2.txt
 compare_nole ${REFERENCE}/format2.txt ${TMPDIR}/format2.txt
@@ -16,7 +16,7 @@ compare_nole ${REFERENCE}/format1.txt ${TMPDIR}/format1.txt
 gpsbabel -^0 > ${TMPDIR}/format0.txt
 compare_nole ${REFERENCE}/format0.txt ${TMPDIR}/format0.txt
 gpsbabel -%1 > ${TMPDIR}/filter1.txt
-sed 's,https://www.gpsbabel.org/htmldoc-.[^/]*/,https://www.gpsbabel.org/WEB_DOC_DIR/,' ${TMPDIR}/filter1.txt >${TMPDIR}/filter1.fiddled.txt
+sed 's,file:///usr/share/doc/gpsbabel/,https://www.gpsbabel.org/WEB_DOC_DIR/,' ${TMPDIR}/filter1.txt >${TMPDIR}/filter1.fiddled.txt
 compare_nole ${REFERENCE}/filter1.txt ${TMPDIR}/filter1.fiddled.txt
 gpsbabel -%0 > ${TMPDIR}/filter0.txt
 compare_nole ${REFERENCE}/filter0.txt ${TMPDIR}/filter0.txt
--- a/xmldoc/gpsbabel_man.xml
+++ b/xmldoc/gpsbabel_man.xml
@@ -127,7 +127,7 @@ or as the backend for other tools. </para>
         </listitem>
       </varlistentry>
     </variablelist>
-    <para>Lists of filters and formats are given in the doc at https://www.gpsbabel.org. </para>
+    <para>Lists of filters and formats are given in the doc at /usr/share/doc/gpsbabel/. </para>
   </refsect1>
   <refsect1>
     <title>See Also</title>
