diff --git a/src/structs.h b/src/structs.h
index 47999a9..66d57e0 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -397,6 +397,8 @@
     char_u	*ul_line;	// text of the line
     long	ul_len;		// length of the line including NUL, plus text
 				// properties
+    colnr_T	ul_textlen;	// length of the line excluding NUL and any text
+				// properties
 } undoline_T;
 
 typedef struct u_entry u_entry_T;