diff --git a/include/crucible/fd.h b/include/crucible/fd.h
index 9818819..f905812 100644
--- a/include/crucible/fd.h
+++ b/include/crucible/fd.h
@@ -146,6 +146,7 @@ namespace crucible {
 	};
 
 	int ioctl_iflags_get(int fd);
+	void ioctl_iflags_set(int fd, int attr);
 
 	string st_mode_ntoa(mode_t mode);
 
diff --git a/lib/fd.cc b/lib/fd.cc
index 931167f..be6177b 100644
--- a/lib/fd.cc
+++ b/lib/fd.cc
@@ -496,6 +496,12 @@ namespace crucible {
 		return attr;
 	}
 
+	void
+	ioctl_iflags_set(int fd, int attr)
+	{
+		DIE_IF_MINUS_ONE(ioctl(fd, FS_IOC_SETFLAGS, &attr));
+	}
+
 	string
 	readlink_or_die(const string &path)
 	{