diff --git a/src/engine/jam.h b/src/engine/jam.h
index 86ad0e86b..497a5bfb1 100644
--- a/src/engine/jam.h
+++ b/src/engine/jam.h
@@ -409,7 +409,7 @@
 #define MAXSYM   1024  /* longest symbol in the environment */
 #define MAXJPATH 1024  /* longest filename */
 
-#define MAXJOBS  64    /* internally enforced -j limit */
+#define MAXJOBS  256   /* internally enforced -j limit */
 #define MAXARGC  32    /* words in $(JAMSHELL) */
 
 /* Jam private definitions below. */