diff --git a/extra/python/build b/extra/python/build
index 26f169a1..05baf42c 100755
--- a/extra/python/build
+++ b/extra/python/build
@@ -1,14 +1,5 @@
 #!/bin/sh -e
 
-# Without this environment variable being set to some arbitrary value,
-# python's module loader uses timestamps for cache invalidation. Something
-# goes wrong here and all pyc files are seen as stale.
-#
-# By setting this value, python uses checksums for cache invalidation which
-# (on my machine) drops startup time from 3 seconds to 0.060s. Further
-# investigation is needed.
-export SOURCE_DATE_EPOCH=1628593994
-
 # Remove util-linux dependency among other things.
 cat >> Modules/Setup <<EOF
 *disabled*
@@ -20,7 +11,9 @@ EOF
 export CFLAGS="$CFLAGS -fno-semantic-interposition"
 export LDFLAGS="$LDFLAGS -fno-semantic-interposition"
 
-patch -p1 < python3-always-pip.patch
+for patch in *.patch; do
+    patch -p1 < "$patch"
+done
 
 ./configure \
     --prefix=/usr \
@@ -36,9 +29,6 @@ make install
 ln -s python3 "$1/usr/bin/python"
 ln -s pip3    "$1/usr/bin/pip"
 
-# Make static library writable.
-chmod u+w "$1/usr/lib/libpython"*
-
 # Let's make some kind of effort to reduce the overall
 # size of Python by removing a bunch of rarely used and
 # otherwise useless components.
diff --git a/extra/python/checksums b/extra/python/checksums
index 259b452c..c79f1d39 100644
--- a/extra/python/checksums
+++ b/extra/python/checksums
@@ -1,2 +1,4 @@
 397920af33efc5b97f2e0b57e91923512ef89fc5b3c1d21dbfc8c4828ce0108a
 1e3dd58370fa3f5c9454f72479565e5282d16defdeec43c88e9a4dd233e00c1b
+18ec738f531ff250c96b74f80bdba58433a39302ab69895593cc2fa2bdf4d0aa
+e39e9562cf5b864500ef358960545787761fc4271829d22b19c893d1ce0e4546
diff --git a/extra/python/patches/python3-no-static.patch b/extra/python/patches/python3-no-static.patch
new file mode 100644
index 00000000..da9bf92d
--- /dev/null
+++ b/extra/python/patches/python3-no-static.patch
@@ -0,0 +1,52 @@
+diff --git a/Makefile.pre.in b/Makefile.pre.in
+index 2b68571..41871c9 100644
+--- a/Makefile.pre.in
++++ b/Makefile.pre.in
+@@ -589,7 +589,7 @@ clinic: check-clean-src $(srcdir)/Modules/_blake2/blake2s_impl.c
+ 	$(PYTHON_FOR_REGEN) $(srcdir)/Tools/clinic/clinic.py --make --srcdir $(srcdir)
+ 
+ # Build the interpreter
+-$(BUILDPYTHON):	Programs/python.o $(LIBRARY) $(LDLIBRARY) $(PY3LIBRARY) $(EXPORTSYMS)
++$(BUILDPYTHON):	Programs/python.o $(LDLIBRARY) $(PY3LIBRARY) $(EXPORTSYMS)
+ 	$(LINKCC) $(PY_CORE_LDFLAGS) $(LINKFORSHARED) -o $@ Programs/python.o $(BLDLIBRARY) $(LIBS) $(MODLIBS) $(SYSLIBS)
+ 
+ platform: $(BUILDPYTHON) pybuilddir.txt
+@@ -638,11 +638,6 @@ sharedmods: $(BUILDPYTHON) pybuilddir.txt Modules/_math.o
+ 		$(PYTHON_FOR_BUILD) $(srcdir)/setup.py $$quiet build
+ 
+ 
+-# Build static library
+-$(LIBRARY): $(LIBRARY_OBJS)
+-	-rm -f $@
+-	$(AR) $(ARFLAGS) $@ $(LIBRARY_OBJS)
+-
+ libpython$(LDVERSION).so: $(LIBRARY_OBJS) $(DTRACE_OBJS)
+ 	if test $(INSTSONAME) != $(LDLIBRARY); then \
+ 		$(BLDSHARED) -Wl,-h$(INSTSONAME) -o $(INSTSONAME) $(LIBRARY_OBJS) $(MODLIBS) $(SHLIBS) $(LIBC) $(LIBM); \
+@@ -724,7 +719,7 @@ Makefile Modules/config.c: Makefile.pre \
+ 	@echo "The Makefile was updated, you may need to re-run make."
+ 
+ 
+-Programs/_testembed: Programs/_testembed.o $(LIBRARY) $(LDLIBRARY) $(PY3LIBRARY) $(EXPORTSYMS)
++Programs/_testembed: Programs/_testembed.o $(LDLIBRARY) $(PY3LIBRARY) $(EXPORTSYMS)
+ 	$(LINKCC) $(PY_CORE_LDFLAGS) $(LINKFORSHARED) -o $@ Programs/_testembed.o $(BLDLIBRARY) $(LIBS) $(MODLIBS) $(SYSLIBS)
+ 
+ ############################################################################
+@@ -1652,17 +1647,6 @@ libainstall:	@DEF_MAKE_RULE@ python-config
+ 		else	true; \
+ 		fi; \
+ 	done
+-	@if test -d $(LIBRARY); then :; else \
+-		if test "$(PYTHONFRAMEWORKDIR)" = no-framework; then \
+-			if test "$(SHLIB_SUFFIX)" = .dll; then \
+-				$(INSTALL_DATA) $(LDLIBRARY) $(DESTDIR)$(LIBPL) ; \
+-			else \
+-				$(INSTALL_DATA) $(LIBRARY) $(DESTDIR)$(LIBPL)/$(LIBRARY) ; \
+-			fi; \
+-		else \
+-			echo Skip install of $(LIBRARY) - use make frameworkinstall; \
+-		fi; \
+-	fi
+ 	$(INSTALL_DATA) Modules/config.c $(DESTDIR)$(LIBPL)/config.c
+ 	$(INSTALL_DATA) Programs/python.o $(DESTDIR)$(LIBPL)/python.o
+ 	$(INSTALL_DATA) $(srcdir)/Modules/config.c.in $(DESTDIR)$(LIBPL)/config.c.in
diff --git a/extra/python/patches/python3-pyc-hash.patch b/extra/python/patches/python3-pyc-hash.patch
new file mode 100644
index 00000000..db81167e
--- /dev/null
+++ b/extra/python/patches/python3-pyc-hash.patch
@@ -0,0 +1,16 @@
+diff --git a/Lib/py_compile.py b/Lib/py_compile.py
+index a81f493..e1328ed 100644
+--- a/Lib/py_compile.py
++++ b/Lib/py_compile.py
+@@ -70,10 +70,7 @@ class PycInvalidationMode(enum.Enum):
+
+
+ def _get_default_invalidation_mode():
+-    if os.environ.get('SOURCE_DATE_EPOCH'):
+-        return PycInvalidationMode.CHECKED_HASH
+-    else:
+-        return PycInvalidationMode.TIMESTAMP
++    return PycInvalidationMode.CHECKED_HASH
+
+
+ def compile(file, cfile=None, dfile=None, doraise=False, optimize=-1,
diff --git a/extra/python/sources b/extra/python/sources
index c9afa3e6..8952dfbc 100644
--- a/extra/python/sources
+++ b/extra/python/sources
@@ -1,2 +1,4 @@
 https://www.python.org/ftp/python/VERSION/Python-VERSION.tar.xz
 patches/python3-always-pip.patch
+patches/python3-no-static.patch
+patches/python3-pyc-hash.patch