diff --git a/network/bird/bird.SlackBuild b/network/bird/bird.SlackBuild
index 94ea03d2c8..cd85b8b870 100644
--- a/network/bird/bird.SlackBuild
+++ b/network/bird/bird.SlackBuild
@@ -50,7 +50,7 @@ find -L . \
  \( -perm 666 -o -perm 664 -o -perm 640 -o -perm 600 -o -perm 444 \
  -o -perm 440 -o -perm 400 \) -exec chmod 644 {} \;
 
-CFLAGS="$SLKCFLAGS" \
+CFLAGS="$SLKCFLAGS -fgnu89-inline" \
 CXXFLAGS="$SLKCFLAGS" \
 ./configure \
   --prefix=/usr \