diff --git a/src/common.h b/src/common.h
index 3a550b8..28d8d10 100644
--- a/src/common.h
+++ b/src/common.h
@@ -153,7 +153,7 @@
 #define LY_VCODE_INDEV       LYVE_SYNTAX_YANG, "Deviate \"%s\" does not support keyword \"%s\"."
 #define LY_VCODE_INREGEXP    LYVE_SYNTAX_YANG, "Regular expression \"%s\" is not valid (\"%s\": %s)."
 #define LY_VCODE_XP_EOE      LYVE_XPATH, "Unterminated string delimited with %c (%.15s)."
-#define LY_VCODE_XP_INEXPR   LYVE_XPATH, "Invalid expression 0x%x."
+#define LY_VCODE_XP_INEXPR   LYVE_XPATH, "Invalid character number %u of expression \'%s\'."
 
 /******************************************************************************
  * Context
diff --git a/src/xpath.c b/src/xpath.c
index 6e25cb9..94cb734 100644
--- a/src/xpath.c
+++ b/src/xpath.c
@@ -35,11 +35,12 @@
  *
  * @return Length of \p ncname valid bytes.
  */
-static size_t
+static long int
 parse_ncname(const char *ncname)
 {
     unsigned int uc;
-    size_t size, len = 0;
+    size_t size;
+    long int len = 0;
 
     LY_CHECK_RET(ly_getutf8(&ncname, &uc, &size), 0);
     if (!is_xmlqnamestartchar(uc) || (uc == ':')) {
@@ -51,7 +52,7 @@
         if (!*ncname) {
             break;
         }
-        LY_CHECK_RET(ly_getutf8(&ncname, &uc, &size), 0);
+        LY_CHECK_RET(ly_getutf8(&ncname, &uc, &size), -len);
     } while (is_xmlqnamechar(uc) && (uc != ':'));
 
     return len;
@@ -121,7 +122,8 @@
 lyxp_expr_parse(struct ly_ctx *ctx, const char *expr)
 {
     struct lyxp_expr *ret;
-    size_t parsed = 0, tok_len, ncname_len;
+    size_t parsed = 0, tok_len;
+    long int ncname_len;
     enum lyxp_token tok_type;
     int prev_function_check = 0;
 
@@ -308,7 +310,7 @@
                        expr[parsed], &expr[parsed], ret->tok_len[ret->used - 1], &ret->expr[ret->tok_pos[ret->used - 1]]);
                 goto error;
             } else {
-                LOGVAL(ctx, LY_VLOG_NONE, NULL, LY_VCODE_XP_INEXPR, expr[parsed], &expr[parsed]);
+                LOGVAL(ctx, LY_VLOG_NONE, NULL, LY_VCODE_XP_INEXPR, parsed + 1, expr);
                 goto error;
             }
         } else if (expr[parsed] == '*') {
@@ -321,7 +323,7 @@
 
             /* NameTest (NCName ':' '*' | QName) or NodeType/FunctionName */
             ncname_len = parse_ncname(&expr[parsed]);
-            LY_CHECK_ERR_GOTO(!ncname_len, LOGVAL(ctx, LY_VLOG_NONE, NULL, LY_VCODE_XP_INEXPR, expr[parsed], &expr[parsed]), error);
+            LY_CHECK_ERR_GOTO(ncname_len < 0, LOGVAL(ctx, LY_VLOG_NONE, NULL, LY_VCODE_XP_INEXPR, parsed - ncname_len + 1, expr), error);
             tok_len = ncname_len;
 
             if (expr[parsed + tok_len] == ':') {
@@ -330,7 +332,7 @@
                     ++tok_len;
                 } else {
                     ncname_len = parse_ncname(&expr[parsed + tok_len]);
-                    LY_CHECK_ERR_GOTO(!ncname_len, LOGVAL(ctx, LY_VLOG_NONE, NULL, LY_VCODE_XP_INEXPR, expr[parsed], &expr[parsed]), error);
+                    LY_CHECK_ERR_GOTO(ncname_len < 0, LOGVAL(ctx, LY_VLOG_NONE, NULL, LY_VCODE_XP_INEXPR, parsed - ncname_len + 1, expr), error);
                     tok_len += ncname_len;
                 }
                 /* remove old flag to prevent ambiguities */