diff --git a/src/os/darwin/darwin_sigar.c b/src/os/darwin/darwin_sigar.c
index 5dd477cd..bf691130 100644
--- a/src/os/darwin/darwin_sigar.c
+++ b/src/os/darwin/darwin_sigar.c
@@ -288,7 +288,18 @@ int sigar_mem_get(sigar_t *sigar, sigar_mem_t *mem)
 
 #define SWI_MAXMIB 3
 
-#ifdef SIGAR_FREEBSD5
+#ifndef XSWDEV_VERSION
+#define XSWDEV_VERSION  1
+struct xswdev {
+    u_int   xsw_version;
+    udev_t  xsw_dev;
+    int     xsw_flags;
+    int     xsw_nblks;
+    int     xsw_used;
+};
+#endif
+
+#ifdef __FreeBSD__
 /* code in this function is based on FreeBSD 5.3 kvm_getswapinfo.c */
 static int getswapinfo_sysctl(struct kvm_swap *swap_ary,
                               int swap_max) 
@@ -354,8 +365,6 @@ static int getswapinfo_sysctl(struct kvm_swap *swap_ary,
 
     return SIGAR_OK;
 }
-#else
-#define getswapinfo_sysctl(swap_ary, swap_max) SIGAR_ENOTIMPL
 #endif
 
 int sigar_swap_get(sigar_t *sigar, sigar_swap_t *swap)