diff --git a/vg_include.h b/vg_include.h
index e81fe77..3b8358f 100644
--- a/vg_include.h
+++ b/vg_include.h
@@ -130,7 +130,7 @@
    scheduler algorithms is surely O(N) in the number of threads, since
    that's simple, at least.  And (in practice) we hope that most
    programs do not need many threads. */
-#define VG_N_THREADS 50
+#define VG_N_THREADS 20
 
 /* Maximum number of pthread keys available.  Again, we start low until
    the need for a higher number presents itself. */