diff --git a/src/expression.c b/src/expression.c
index 354b805..0e4e2a1 100644
--- a/src/expression.c
+++ b/src/expression.c
@@ -1,5 +1,5 @@
 #include "expression.h"
-#include "fieldset.H"
+#include "fieldset.h"
 
 #include "../lib/xalloc.h"