diff --git a/src/unix/freebsd/disk.rs b/src/unix/freebsd/disk.rs
index ab3908854..c19ce8f8e 100644
--- a/src/unix/freebsd/disk.rs
+++ b/src/unix/freebsd/disk.rs
@@ -58,6 +58,11 @@ impl DiskInner {
             refresh_disk(self, &mut vfs)
         }
     }
+
+    pub(crate) fn usage(&self) -> DiskUsage {
+        // TODO: Until disk i/o stats are added, return the default
+        DiskUsage::default()
+    }
 }
 
 impl crate::DisksInner {
@@ -78,6 +83,12 @@ impl crate::DisksInner {
     pub(crate) fn list_mut(&mut self) -> &mut [Disk] {
         &mut self.disks
     }
+
+    pub(crate) fn refresh(&mut self) {
+        for disk in self.list_mut() {
+            disk.refresh();
+        }
+    }
 }
 
 // FIXME: if you want to get disk I/O usage:
diff --git a/src/unknown/disk.rs b/src/unknown/disk.rs
index af2183f1f..901c3114b 100644
--- a/src/unknown/disk.rs
+++ b/src/unknown/disk.rs
@@ -42,6 +42,10 @@ impl DiskInner {
     pub(crate) fn refresh(&mut self) -> bool {
         true
     }
+
+    pub(crate) fn usage(&self) -> DiskUsage {
+        unreachable!()
+    }
 }
 
 pub(crate) struct DisksInner {
@@ -65,6 +69,10 @@ impl DisksInner {
         // Does nothing.
     }
 
+    pub(crate) fn refresh(&mut self) {
+        // Does nothing.
+    }
+
     pub(crate) fn list(&self) -> &[Disk] {
         &self.disks
     }