diff --git a/build-aux/build-ports.sh b/build-aux/build-ports.sh
index d3f584cb..5f21d35f 100755
--- a/build-aux/build-ports.sh
+++ b/build-aux/build-ports.sh
@@ -291,6 +291,7 @@ extract_package() {(
   PACKAGE="$1"
   unset ARCHIVE
   unset ARCHIVE_2
+  unset NEED_WRITABLE
   . "$SORTIX_PORTS_DIR/$PACKAGE/$PACKAGE.info"
   # TODO: Only reextract if actually needed.
   rm -rf "$SORTIX_PORTS_DIR/$PACKAGE/$PACKAGE"
@@ -312,7 +313,9 @@ extract_package() {(
   if [ -f "$SORTIX_PORTS_DIR/$PACKAGE/$PACKAGE.normalize" ]; then
     tix-rmpatch --directory "$SORTIX_PORTS_DIR/$PACKAGE/$PACKAGE" "$SORTIX_PORTS_DIR/$PACKAGE/$PACKAGE.normalize"
   fi
-  find "$SORTIX_PORTS_DIR/$PACKAGE/$PACKAGE" '!' -type d -exec chmod -w '{}' +
+  if [ "$NEED_WRITABLE" != true ]; then
+    find "$SORTIX_PORTS_DIR/$PACKAGE/$PACKAGE" '!' -type d -exec chmod -w '{}' +
+  fi
 )}
 
 # Build all the packages (if needed) and otherwise install them.
diff --git a/ports/python/python.info b/ports/python/python.info
index 49db35de..087a65b9 100644
--- a/ports/python/python.info
+++ b/ports/python/python.info
@@ -6,3 +6,4 @@ ARCHIVE='Python-3.6.0.tar.xz'
 SHA256SUM='b0c5f904f685e32d9232f7bdcbece9819a892929063b6e385414ad2dd6a23622'
 UPSTREAM_SITE='https://www.python.org/ftp/python/3.6.0'
 UPSTREAM_ARCHIVE='Python-3.6.0.tar.xz'
+NEED_WRITABLE=true
diff --git a/portsify.sh b/portsify.sh
index 12ffef9d..d72a13ae 100755
--- a/portsify.sh
+++ b/portsify.sh
@@ -20,7 +20,6 @@ for port in $ports; do
   esac
   if [ -e "$portsdir/$port/$port.info" ]; then
     continue
-    :
   fi
   tar -xf "$porttixdir/$port.porttix.tar.xz"
   tar -xf "$srctixdir/$port.srctix.tar.xz" "$port/tixbuildinfo"
@@ -54,6 +53,7 @@ for port in $ports; do
     rm -rf "$port.srctix"
     files="sortix-libSDL-1.2.15.tar.xz"
   fi
+  NEED_WRITABLE=
   case "$port" in
   bison|grep|tar|wget)
     echo "rm -rf -- 'doc/stamp-vti'" >> "patch.normalize"
@@ -81,8 +81,9 @@ for port in $ports; do
     ;;
   python)
     echo "rm -rf -- 'Python/graminit.c'" >> "patch.normalize"
-    # TODO: This file has to exist and be writeable. Sigh.
+    # This file has to exist and be writeable. Sigh.
     #echo "rm -rf -- 'Include/graminit.h'" >> "patch.normalize"
+    NEED_WRITABLE=true
     echo "rm -rf -- 'Python/importlib_external.h'" >> "patch.normalize"
     echo "rm -rf -- 'Python/importlib.h'" >> "patch.normalize"
     ;;
@@ -105,6 +106,7 @@ for port in $ports; do
     rmdir "$port.normalized"
     rm -rf "$port.srctix"
   fi
+  # TODO: Extract post-install.sortix from patch.
   file_number=0
   for file in $files; do
     file_number=$(expr $file_number + 1)
@@ -202,6 +204,9 @@ for port in $ports; do
       touch -r "$mirrordir/$port/$file" "$mirrordir/$port"
     fi
   done
+  if [ -n "$NEED_WRITABLE" ]; then
+    echo "NEED_WRITABLE=$NEED_WRITABLE" >> "$port.info.new"
+  fi
   rm -f "$portsdir/$port/porttixinfo"
   rm -f "$portsdir/$port/tixbuildinfo"
   if [ "$port" != patch ]; then