diff --git a/src/term.rs b/src/term.rs
index 7f69b544583e3fcd6f9de0f38fbeece4b59de1f1..15b9b0d5b24f724a7e292c2040509eec280bb598 100644
--- a/src/term.rs
+++ b/src/term.rs
@@ -16,7 +16,7 @@ mod c {
     #[cfg(any(target_os = "linux", target_os = "android"))]
     static TIOCGWINSZ: c_ulong = 0x5413;
 
-    #[cfg(any(target_os = "macos", target_os = "ios"))]
+    #[cfg(any(target_os = "macos", target_os = "ios", target_os = "dragonfly"))]
     static TIOCGWINSZ: c_ulong = 0x40087468;
 
     extern {