1 files changed, 1 insertions, 0 deletions
diff --git a/parse.y b/parse.y
index 3b58fd6874..3021565888 100644
--- a/parse.y
+++ b/parse.y
@@ -19,6 +19,7 @@
 #include "st.h"
 #include <stdio.h>
 #include <errno.h>
+#include <ctype.h>
 
 #define ID_SCOPE_SHIFT 3
 #define ID_SCOPE_MASK 0x07