diff --git a/lib/sl/test_sl.c b/lib/sl/test_sl.c
index 244be8936..31b1fee3a 100644
--- a/lib/sl/test_sl.c
+++ b/lib/sl/test_sl.c
@@ -30,7 +30,7 @@
  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */
 
-#include "sl_locl.H"
+#include "sl_locl.h"
 
 RCSID("$Id$");