diff --git a/bootstrap b/bootstrap
index c13b486c5..5b08e7e2d 100755
--- a/bootstrap
+++ b/bootstrap
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Print a version string.
-scriptversion=2018-10-13.05; # UTC
+scriptversion=2019-01-04.17; # UTC
 
 # Bootstrap this package from checked-out sources.
 
@@ -963,6 +963,16 @@ fi
 bootstrap_post_import_hook \
   || die "bootstrap_post_import_hook failed"
 
+# Don't proceed if there are uninitialized submodules.  In particular,
+# the next step will remove dangling links, which might be links into
+# uninitialized submodules.
+#
+# Uninitialized submodules are listed with an initial dash.
+if $use_git && git submodule | grep '^-' >/dev/null; then
+  die "some git submodules are not initialized. "     \
+      "Run 'git submodule init' and bootstrap again."
+fi
+
 # Remove any dangling symlink matching "*.m4" or "*.[ch]" in some
 # gnulib-populated directories.  Such .m4 files would cause aclocal to fail.
 # The following requires GNU find 4.2.3 or newer.  Considering the usual
diff --git a/gnulib b/gnulib
index 4652c7baf..8da562a8a 160000
--- a/gnulib
+++ b/gnulib
@@ -1 +1 @@
-Subproject commit 4652c7bafa60332145f1e05a7de5f48e1bc56226
+Subproject commit 8da562a8ae58c5924b560c57e0e2bd88156ac9bd