diff --git a/Lib/lib2to3/pgen2/driver.py b/Lib/lib2to3/pgen2/driver.py
index e7828ff..4c611c6 100644
--- a/Lib/lib2to3/pgen2/driver.py
+++ b/Lib/lib2to3/pgen2/driver.py
@@ -138,3 +138,20 @@
     if not os.path.exists(b):
         return True
     return os.path.getmtime(a) >= os.path.getmtime(b)
+
+
+def main(*args):
+    """Main program, when run as a script: produce grammar pickle files.
+
+    Calls load_grammar for each argument, a path to a grammar text file.
+    """
+    if not args:
+        args = sys.argv[1:]
+    logging.basicConfig(level=logging.INFO, stream=sys.stdout,
+                        format='%(message)s')
+    for gt in args:
+        load_grammar(gt, save=True, force=True)
+    return True
+
+if __name__ == "__main__":
+    sys.exit(int(not main()))
diff --git a/Makefile.pre.in b/Makefile.pre.in
index f715711..d42c938 100644
--- a/Makefile.pre.in
+++ b/Makefile.pre.in
@@ -1017,8 +1017,6 @@
 		venv venv/scripts venv/scripts/posix \
 		curses pydoc_data $(MACHDEPS)
 libinstall:	build_all $(srcdir)/Lib/$(PLATDIR) $(srcdir)/Modules/xxmodule.c
-	-PYTHONPATH=$(DESTDIR)$(LIBDEST) $(RUNSHARED) \
-		$(PYTHON_FOR_BUILD) -Wi -c "import lib2to3.pygram, lib2to3.patcomp;lib2to3.patcomp.PatternCompiler()"
 	@for i in $(SCRIPTDIR) $(LIBDEST); \
 	do \
 		if test ! -d $(DESTDIR)$$i; then \
@@ -1096,6 +1094,10 @@
 		$(PYTHON_FOR_BUILD) -Wi -O $(DESTDIR)$(LIBDEST)/compileall.py \
 		-d $(LIBDEST)/site-packages -f \
 		-x badsyntax $(DESTDIR)$(LIBDEST)/site-packages
+	-PYTHONPATH=$(DESTDIR)$(LIBDEST) $(RUNSHARED) \
+		$(PYTHON_FOR_BUILD) -m lib2to3.pgen2.driver $(DESTDIR)$(LIBDEST)/lib2to3/Grammar.txt
+	-PYTHONPATH=$(DESTDIR)$(LIBDEST) $(RUNSHARED) \
+		$(PYTHON_FOR_BUILD) -m lib2to3.pgen2.driver $(DESTDIR)$(LIBDEST)/lib2to3/PatternGrammar.txt
 
 # Create the PLATDIR source directory, if one wasn't distributed..
 $(srcdir)/Lib/$(PLATDIR):
@@ -1340,7 +1342,7 @@
 	find . -name '*.so.[0-9]*.[0-9]*' -exec rm -f {} ';'
 	find build -name 'fficonfig.h' -exec rm -f {} ';' || true
 	find build -name 'fficonfig.py' -exec rm -f {} ';' || true
-	-rm -f $(srcdir)/Lib/lib2to3/*Grammar*.pickle
+	-rm -f Lib/lib2to3/*Grammar*.pickle
 	-rm -f $(SYSCONFIGDATA)
 	-rm -f Modules/_testembed Modules/_freeze_importlib
 
diff --git a/Misc/NEWS b/Misc/NEWS
index 802d984..12e4c4a 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -141,6 +141,9 @@
 Tools/Demos
 -----------
 
+- Issue #15822: Really ensure 2to3 grammar pickles are properly installed
+  (replaces fixes for Issue #15645).
+
 Documentation
 -------------