diff --git a/mach/ns/libbc/compmodule b/mach/ns/libbc/compmodule
index 491f6d251..6b9643943 100755
--- a/mach/ns/libbc/compmodule
+++ b/mach/ns/libbc/compmodule
@@ -1,2 +1,4 @@
-${MACH?} -I../../../h ${MACHFL?} $1 1>&2
-echo `basename $1 $2`.o
+if ${MACH?ack} -I../../../h ${MACHFL?} $1 1>&2
+then echo `basename $1 $2`.o
+else rm -f `basename $1 $2`.o
+fi
diff --git a/mach/ns/libcc/compmodule b/mach/ns/libcc/compmodule
index 491f6d251..6b9643943 100755
--- a/mach/ns/libcc/compmodule
+++ b/mach/ns/libcc/compmodule
@@ -1,2 +1,4 @@
-${MACH?} -I../../../h ${MACHFL?} $1 1>&2
-echo `basename $1 $2`.o
+if ${MACH?ack} -I../../../h ${MACHFL?} $1 1>&2
+then echo `basename $1 $2`.o
+else rm -f `basename $1 $2`.o
+fi