diff --git a/src/structs.h b/src/structs.h
index d8c6aef..eefc8f2 100644
--- a/src/structs.h
+++ b/src/structs.h
@@ -4764,14 +4764,22 @@
     MAGIC_ALL = 4		// "\v" very magic
 } magic_T;
 
+typedef enum {
+    WT_UNKNOWN = 0,	// Unknown or unspecified location
+    WT_ARGUMENT,
+    WT_VARIABLE,
+    WT_MEMBER,
+    WT_METHOD,
+} wherekind_T;
+
 // Struct used to pass to error messages about where the error happened.
 typedef struct {
-    char    *wt_func_name;  // function name or NULL
-    char    wt_index;	    // argument or variable index, 0 means unknown
-    char    wt_variable;    // "variable" when TRUE, "argument" otherwise
+    char	*wt_func_name;  // function name or NULL
+    char	wt_index;	// argument or variable index, 0 means unknown
+    wherekind_T	wt_kind;	// "variable" when TRUE, "argument" otherwise
 } where_T;
 
-#define WHERE_INIT {NULL, 0, 0}
+#define WHERE_INIT {NULL, 0, WT_UNKNOWN}
 
 // Struct passed to get_v_event() and restore_v_event().
 typedef struct {