diff --git a/lib/libkvm/kvm.c b/lib/libkvm/kvm.c
index 8ce148eb019f..32ff245c1499 100644
--- a/lib/libkvm/kvm.c
+++ b/lib/libkvm/kvm.c
@@ -253,7 +253,7 @@ kvm_t *
 kvm_openfiles(uf, mf, sf, flag, errout)
 	const char *uf;
 	const char *mf;
-	const char *sf;
+	const char *sf __unused;
 	int flag;
 	char *errout;
 {
@@ -272,7 +272,7 @@ kvm_t *
 kvm_open(uf, mf, sf, flag, errstr)
 	const char *uf;
 	const char *mf;
-	const char *sf;
+	const char *sf __unused;
 	int flag;
 	const char *errstr;
 {
diff --git a/lib/libkvm/kvm_open.3 b/lib/libkvm/kvm_open.3
index 04990b4e9ded..c0378504f640 100644
--- a/lib/libkvm/kvm_open.3
+++ b/lib/libkvm/kvm_open.3
@@ -87,11 +87,9 @@ the default indicated by
 .Dv _PATH_MEM
 from <paths.h> is used.
 .Pp
+The
 .Fa swapfile
-should indicate the swap device.  If
-.Dv NULL ,
-.Dv _PATH_DRUM
-from <paths.h> is used.
+argument is currently unused.
 .Pp
 The
 .Fa flags