diff --git a/src/core/peg.c b/src/core/peg.c
index 904befa0..30133cab 100644
--- a/src/core/peg.c
+++ b/src/core/peg.c
@@ -402,9 +402,6 @@ tail:
                 s->mode = oldmode;
                 if (!result) return NULL;
 
-                /* Add matched text */
-                pushcap(s, janet_stringv(text, (int32_t)(result - text)), text, result);
-
                 /* Now check captures with provided function */
                 int32_t argc = s->captures->count - cs.cap;
                 Janet *argv = s->captures->data + cs.cap;
@@ -417,11 +414,12 @@ tail:
                     cap = cfun(argc, argv);
                 }
 
+                cap_load(s, cs);
+
                 /* Capture failed */
-                if (janet_checktype(cap, JANET_NIL)) return NULL;
+                if (!janet_truthy(cap)) return NULL;
 
                 /* Capture worked, so use new capture */
-                cap_load(s, cs);
                 pushcap(s, cap, text, result);
 
                 return result;
@@ -698,9 +696,9 @@ static void spec_reference(Builder *b, int32_t argc, const Janet *argv) {
     Reserve r = reserve(b, 2);
     int32_t index = peg_getinteger(b, argv[0]);
     if (index < 0) {
-        emit_1(r, RULE_BACKINDEX, -index);
+        emit_1(r, RULE_REPINDEX, -index - 1);
     } else {
-        emit_1(r, RULE_REPINDEX, index);
+        emit_1(r, RULE_BACKINDEX, index);
     }
 }
 
diff --git a/test/suite3.janet b/test/suite3.janet
index 985c568e..fd012dc2 100644
--- a/test/suite3.janet
+++ b/test/suite3.janet
@@ -182,6 +182,7 @@
 (check-match '(* (some (range "az" "AZ")) -1) "hello" true)
 (check-match '(* (some (range "az" "AZ")) -1) "hello world" false)
 (check-match '(* (some (range "az" "AZ")) -1) "1he11o" false)
+(check-match '(* (some (range "az" "AZ")) -1) "" false)
 
 # Pre compile
 
@@ -271,7 +272,7 @@
 
 # Matchtime capture
 
-(def scanner (peg/compile ~(cmt (some 1) ,scan-number)))
+(def scanner (peg/compile ~(cmt (capture (some 1)) ,scan-number)))
 
 (check-deep scanner "123" @[123])
 (check-deep scanner "0x86" @[0x86])
@@ -287,4 +288,35 @@
 (check-match g "aacbb" true)
 (check-match g "aadbb" false)
 
+# Back reference
+
+(def wrapped-string
+  ~{:pad (any "=")
+    :open (* "[" (capture :pad) "[")
+    :close (* "]" (cmt (* (backref 0) (capture :pad)) ,=) "]")
+    :main (* :open (any (if-not 1 :close)) :close -1)})
+
+(check-match wrapped-string "[[]]" true)
+(check-match wrapped-string "[==[a]==]" true)
+(check-match wrapped-string "[==[]===]" false)
+(check-match wrapped-string "[[blark]]" true)
+(check-match wrapped-string "[[bl[ark]]" true)
+(check-match wrapped-string "[[bl]rk]]" true)
+(check-match wrapped-string "[[bl]rk]] " false)
+(check-match wrapped-string "[=[bl]]rk]=] " false)
+(check-match wrapped-string "[=[bl]==]rk]=] " false)
+
+(def janet-longstring
+  ~{:open (capture (some "`"))
+    :close (cmt (* (backref 0) :open) ,=)
+    :main (* :open (any (if-not 1 :close)) (not (> -1 "`")) :close -1)})
+
+(check-match janet-longstring "`john" false)
+(check-match janet-longstring "abc" false)
+(check-match janet-longstring "` `" true)
+(check-match janet-longstring "`  `" true)
+(check-match janet-longstring "``  ``" true)
+(check-match janet-longstring "``` `` ```" true)
+(check-match janet-longstring "``  ```" false)
+
 (end-suite)