diff --git a/core/src/main/java/org/jruby/ext/socket/RubyBasicSocket.java b/core/src/main/java/org/jruby/ext/socket/RubyBasicSocket.java
index 861f953fce25..f8aad0571ff0 100644
--- a/core/src/main/java/org/jruby/ext/socket/RubyBasicSocket.java
+++ b/core/src/main/java/org/jruby/ext/socket/RubyBasicSocket.java
@@ -571,7 +571,7 @@ public interface LibC {
         int F_SETFL = jnr.constants.platform.Fcntl.F_SETFL.intValue();
         int O_NONBLOCK = jnr.constants.platform.OpenFlags.O_NONBLOCK.intValue();
 
-        int getsockopt(int s, int level, int optname, @Out ByteBuffer optval, @Out IntByReference optlen);
+        int getsockopt(int s, int level, int optname, @Out ByteBuffer optval, IntByReference optlen);
         int setsockopt(int s, int level, int optname, @In ByteBuffer optval, int optlen);
         int setsockopt(int s, int level, int optname, @In Timeval optval, int optlen);
     }