diff --git a/sys/kern/subr_param.c b/sys/kern/subr_param.c
--- a/sys/kern/subr_param.c
+++ b/sys/kern/subr_param.c
@@ -319,13 +319,19 @@
 	maxprocperuid = (maxproc * 9) / 10;
 
 	/*
-	 * 'maxfiles' by default is set to 32 files per MB (overridable by
-	 * a tunable), and is then clamped at 64 files per MB (which thus never
-	 * happens by default).  (The default MAXFILES is for all practical
-	 * purposes not used, as it gives a lower value than 32 files per MB as
-	 * soon as there is more than ~2.5MB of memory.)
+	 * 'maxfiles' by default is set to 16 files per MB (with a value of 40
+	 * at origin; the final value is overridable by a tunable), and is then
+	 * clamped at 64 files per MB (which thus never happens by default).  16
+	 * files per MB was chosen so that 'maxfiles' always stays below the
+	 * default value automatically chosen by the system for 'maxvnodes', in
+	 * order to mitigate a deadlock situation where some processes can
+	 * deplete all available vnodes, from which we currently cannot recover.
+	 * Mechanisms allowing to create more in-kernel vnodes without file
+	 * descriptors, such as nullfs mount, can nonetheless defeat this
+	 * counter-measure.  Deeper fixes are needed to completely avoid this
+	 * deadlock.
 	 */
-	maxfiles = imax(MAXFILES, pgtok(physpages) / (1024 / 32));
+	maxfiles = imax(MAXFILES, pgtok(physpages) / (1024 / 16));
 	TUNABLE_INT_FETCH("kern.maxfiles", &maxfiles);
 	{
 		const long maxfiles_clamp = pgtok(physpages) / (1024 / 64);