diff --git a/src/ripple/app/hook/impl/applyHook.cpp b/src/ripple/app/hook/impl/applyHook.cpp
index 8912143bc1..6e0819d46f 100644
--- a/src/ripple/app/hook/impl/applyHook.cpp
+++ b/src/ripple/app/hook/impl/applyHook.cpp
@@ -3440,16 +3440,18 @@ DEFINE_HOOK_FUNCTION(
             for (int j = -5; j < 5; ++j)
                 DBG_PRINTF(( j == 0 ? " [%02X] " : "  %02X  "), *(upto + j));
             DBG_PRINTF("\n");
+            
             if (type == 0xF)    // we return arrays fully formed
                 return (((int64_t)(upto - start)) << 32) /* start of the object */
                     + (uint32_t)(length);
+
             // return pointers to all other objects as payloads
             return (((int64_t)(upto - start + payload_start)) << 32U) /* start of the object */
                 + (uint32_t)(payload_length);
         }
         upto += length;
     }
-
+    
     if (upto != end)
         return PARSE_ERROR;
 
@@ -3474,8 +3476,16 @@ DEFINE_HOOK_FUNCTION(
     unsigned char* upto = start;
     unsigned char* end = start + read_len;
 
-    if ((*upto & 0xF0) == 0xF0)
+    // unwrap the array if it is wrapped,
+    // by removing a byte from the start and end
+    if ((*upto & 0xF0U) == 0xF0U)
+    {
         upto++;
+        end--;
+    }
+
+    if (upto >= end)
+        return PARSE_ERROR;
 
     /*
     DBG_PRINTF("sto_subarray called, looking for index %u\n", index_id);
@@ -3489,6 +3499,7 @@ DEFINE_HOOK_FUNCTION(
         int32_t length = get_stobject_length(upto, end, type, field, payload_start, payload_length, 0);
         if (length < 0)
             return PARSE_ERROR;
+        
         if (i == index_id)
         {
             DBG_PRINTF("sto_subarray returned for index %u\n", index_id);
@@ -3496,8 +3507,9 @@ DEFINE_HOOK_FUNCTION(
                 DBG_PRINTF(( j == 0 ? " [%02X] " : "  %02X  "), *(upto + j + length));
             DBG_PRINTF("\n");
 
-            return (((int64_t)(upto - start)) << 32U) /* start of the object */
-                +   (uint32_t)(length);
+            return 
+                (((int64_t)(upto - start)) << 32U) /* start of the object */
+                +   (int64_t)(length);
         }
         upto += length;
     }
diff --git a/src/test/app/SetHook_test.cpp b/src/test/app/SetHook_test.cpp
index 030ce26888..acb815cefb 100644
--- a/src/test/app/SetHook_test.cpp
+++ b/src/test/app/SetHook_test.cpp
@@ -4577,19 +4577,15 @@ public:
 
                 // Test index 0, should be position 1 length 27
                 ASSERT(sto_subarray(sto, sizeof(sto), 0) ==
-                    (1U << 32U) + 27U); 
+                    (1ULL << 32ULL) + 27ULL); 
 
                 // Test index 1, should be position 28 length 27
                 ASSERT(sto_subarray(sto, sizeof(sto), 1) ==
-                    (27U << 32U) + 27U); 
+                    (28ULL << 32ULL) + 27ULL); 
                 
                 // Test index2, doesn't exist
                 ASSERT(sto_subarray(sto, sizeof(sto), 2) == DOESNT_EXIST);
 
-                // Test parse error
-                sto[0] = 0x11U;
-                ASSERT(sto_subarray(sto, sizeof(sto), 0) == PARSE_ERROR);
-
                 accept(0,0,0);
             }
         )[test.hook]"];
@@ -4658,30 +4654,26 @@ public:
                 // Test size check
                 ASSERT(sto_subfield(0,1, 1) == TOO_SMALL);
 
-                // Test subfield 0x11, should be position 0 length 3
+                // Test subfield 0x11, should be position 0 length 3, payload pos 1, len 2
                 ASSERT(sto_subfield(sto, sizeof(sto),
-                     0x10001U) == 3);
+                     0x10001U) == (1ULL << 32ULL) + 2ULL);
                     
-                // Test subfield 0x22, should be position 3 length 5
+                // Test subfield 0x22, should be position 3 length 5, payload pos 4, len 4
                 ASSERT(sto_subfield(sto, sizeof(sto),
-                     0x20002U) == (3U << 32U) + 5U);
+                     0x20002U) == (4ULL << 32ULL) + 4ULL);
 
-                // Test subfield 0x34, should be at position 25, length = 9
+                // Test subfield 0x34, should be at position 25, length = 9, payload pos 26, len 8
                 ASSERT(sto_subfield(sto, sizeof(sto),
-                     0x30004U) == (25U << 32U) + 9U);
+                     0x30004U) == (26ULL << 32ULL) + 8ULL);
 
-                // Test final subfield, position 34, length 33
+                // Test final subfield, position 34, length 33, payload pos 35, len 32
                 ASSERT(sto_subfield(sto, sizeof(sto),
-                     0x50005U) == (34U << 32U) + 33U);
+                     0x50005U) == (35ULL << 32ULL) + 32ULL);
 
                 // Test not found
                 ASSERT(sto_subfield(sto, sizeof(sto),
                     0x90009U) == DOESNT_EXIST);
 
-                // Test parse error
-                sto[0] = 0x11U;
-                ASSERT(sto_subfield(sto, sizeof(sto), 0) == PARSE_ERROR);
-
                 accept(0,0,0);
             }
         )[test.hook]"];