diff --git a/historic/jam/src/Makefile b/historic/jam/src/Makefile
index 90e890983..b78ed1e07 100644
--- a/historic/jam/src/Makefile
+++ b/historic/jam/src/Makefile
@@ -76,7 +76,7 @@ CFLAGS =
 #
 all: jam0
 	chmod a+w jambase.c
-	./jam0
+	./jam0 -sJAMBASE= -sBOOST_ROOT= -sBOOST_BUILD_PATH=
 
 # for other systems
 #all: jam0
diff --git a/jam_src/Makefile b/jam_src/Makefile
index 90e890983..b78ed1e07 100644
--- a/jam_src/Makefile
+++ b/jam_src/Makefile
@@ -76,7 +76,7 @@ CFLAGS =
 #
 all: jam0
 	chmod a+w jambase.c
-	./jam0
+	./jam0 -sJAMBASE= -sBOOST_ROOT= -sBOOST_BUILD_PATH=
 
 # for other systems
 #all: jam0