diff --git a/std/assembly/string.ts b/std/assembly/string.ts
index f9546cb7..1c3a93a9 100644
--- a/std/assembly/string.ts
+++ b/std/assembly/string.ts
@@ -348,23 +348,23 @@ const enum CharCode {
 }
 
 export function parseInt(str: String, radix: i32 = 0): i64 {
-  var len = str.length;
-  var ptr = changetype<usize>(str) + HEAD;
+  var len: i32 = str.length;
   if (!len)
     return 0; // (NaN)
-  var code = <i32>load<u16>(ptr);
+  var ptr = changetype<usize>(str) /* + HEAD -> offset */;
+  var code = <i32>load<u16>(ptr, HEAD);
 
   // determine sign
   var sign: i64;
   if (code == CharCode.MINUS) {
     if (!--len)
       return 0; // (NaN)
-    code = <i32>load<u16>(ptr += 2);
+    code = <i32>load<u16>(ptr += 2, HEAD);
     sign = -1;
   } else if (code == CharCode.PLUS) {
     if (!--len)
       return 0; // (NaN)
-    code = <i32>load<u16>(ptr += 2);
+    code = <i32>load<u16>(ptr += 2, HEAD);
     sign = 1;
   } else
     sign = 1;
@@ -372,7 +372,7 @@ export function parseInt(str: String, radix: i32 = 0): i64 {
   // determine radix
   if (!radix) {
     if (code == CharCode._0 && len > 2) {
-      switch (<i32>load<u16>(ptr + 2)) {
+      switch (<i32>load<u16>(ptr + 2, HEAD)) {
 
         case CharCode.B:
         case CharCode.b:
@@ -396,12 +396,13 @@ export function parseInt(str: String, radix: i32 = 0): i64 {
           radix = 10;
       }
     } else radix = 10;
-  }
+  } else if (radix < 2 || radix > 36)
+    return 0; // (NaN)
 
   // calculate value
   var num: i64 = 0;
   while (len--) {
-    code = <i32>load<u16>(ptr);
+    code = <i32>load<u16>(ptr, HEAD);
     if (code >= CharCode._0 && code <= CharCode._9)
       code -= CharCode._0;
     else if (code >= CharCode.A && code <= CharCode.Z)
diff --git a/tests/compiler/std/string.optimized.wast b/tests/compiler/std/string.optimized.wast
index 1a5e6c17..4e67231a 100644
--- a/tests/compiler/std/string.optimized.wast
+++ b/tests/compiler/std/string.optimized.wast
@@ -375,15 +375,9 @@
   (local $3 i32)
   (local $4 i64)
   (local $5 i64)
-  (set_local $3
-   (i32.add
-    (get_local $0)
-    (i32.const 4)
-   )
-  )
   (if
    (i32.eqz
-    (tee_local $0
+    (tee_local $3
      (i32.load
       (get_local $0)
      )
@@ -397,8 +391,8 @@
    (if (result i64)
     (i32.eq
      (tee_local $2
-      (i32.load16_u
-       (get_local $3)
+      (i32.load16_u offset=4
+       (get_local $0)
       )
      )
      (i32.const 45)
@@ -406,9 +400,9 @@
     (block (result i64)
      (if
       (i32.eqz
-       (tee_local $0
+       (tee_local $3
         (i32.sub
-         (get_local $0)
+         (get_local $3)
          (i32.const 1)
         )
        )
@@ -418,10 +412,10 @@
       )
      )
      (set_local $2
-      (i32.load16_u
-       (tee_local $3
+      (i32.load16_u offset=4
+       (tee_local $0
         (i32.add
-         (get_local $3)
+         (get_local $0)
          (i32.const 2)
         )
        )
@@ -437,9 +431,9 @@
      (block (result i64)
       (if
        (i32.eqz
-        (tee_local $0
+        (tee_local $3
          (i32.sub
-          (get_local $0)
+          (get_local $3)
           (i32.const 1)
          )
         )
@@ -449,10 +443,10 @@
        )
       )
       (set_local $2
-       (i32.load16_u
-        (tee_local $3
+       (i32.load16_u offset=4
+        (tee_local $0
          (i32.add
-          (get_local $3)
+          (get_local $0)
           (i32.const 2)
          )
         )
@@ -465,15 +459,35 @@
    )
   )
   (if
-   (i32.eqz
-    (get_local $1)
+   (get_local $1)
+   (if
+    (i32.and
+     (select
+      (i32.lt_s
+       (get_local $1)
+       (i32.const 2)
+      )
+      (i32.gt_s
+       (get_local $1)
+       (i32.const 36)
+      )
+      (i32.lt_s
+       (get_local $1)
+       (i32.const 2)
+      )
+     )
+     (i32.const 1)
+    )
+    (return
+     (i64.const 0)
+    )
    )
    (set_local $1
     (if (result i32)
      (i32.and
       (select
        (i32.gt_s
-        (get_local $0)
+        (get_local $3)
         (i32.const 2)
        )
        (i32.eq
@@ -496,9 +510,9 @@
            (i32.or
             (i32.eq
              (tee_local $2
-              (i32.load16_u
+              (i32.load16_u offset=4
                (i32.add
-                (get_local $3)
+                (get_local $0)
                 (i32.const 2)
                )
               )
@@ -539,15 +553,15 @@
            (br $case6|0)
           )
          )
-         (set_local $3
+         (set_local $0
           (i32.add
-           (get_local $3)
+           (get_local $0)
            (i32.const 4)
           )
          )
-         (set_local $0
+         (set_local $3
           (i32.sub
-           (get_local $0)
+           (get_local $3)
            (i32.const 2)
           )
          )
@@ -555,15 +569,15 @@
           (i32.const 2)
          )
         )
-        (set_local $3
+        (set_local $0
          (i32.add
-          (get_local $3)
+          (get_local $0)
           (i32.const 4)
          )
         )
-        (set_local $0
+        (set_local $3
          (i32.sub
-          (get_local $0)
+          (get_local $3)
           (i32.const 2)
          )
         )
@@ -571,15 +585,15 @@
          (i32.const 8)
         )
        )
-       (set_local $3
+       (set_local $0
         (i32.add
-         (get_local $3)
+         (get_local $0)
          (i32.const 4)
         )
        )
-       (set_local $0
+       (set_local $3
         (i32.sub
-         (get_local $0)
+         (get_local $3)
          (i32.const 2)
         )
        )
@@ -596,10 +610,10 @@
   (loop $continue|1
    (if
     (block (result i32)
-     (set_local $0
+     (set_local $3
       (i32.sub
        (tee_local $2
-        (get_local $0)
+        (get_local $3)
        )
        (i32.const 1)
       )
@@ -612,8 +626,8 @@
        (select
         (i32.le_s
          (tee_local $2
-          (i32.load16_u
-           (get_local $3)
+          (i32.load16_u offset=4
+           (get_local $0)
           )
          )
          (i32.const 57)
@@ -717,9 +731,9 @@
        )
       )
      )
-     (set_local $3
+     (set_local $0
       (i32.add
-       (get_local $3)
+       (get_local $0)
        (i32.const 2)
       )
      )
diff --git a/tests/compiler/std/string.wast b/tests/compiler/std/string.wast
index 4e9b0aa6..12d9fd9e 100644
--- a/tests/compiler/std/string.wast
+++ b/tests/compiler/std/string.wast
@@ -504,12 +504,6 @@
     (get_local $0)
    )
   )
-  (set_local $3
-   (i32.add
-    (get_local $0)
-    (i32.const 4)
-   )
-  )
   (if
    (i32.eqz
     (get_local $2)
@@ -518,8 +512,11 @@
     (i64.const 0)
    )
   )
+  (set_local $3
+   (get_local $0)
+  )
   (set_local $4
-   (i32.load16_u
+   (i32.load16_u offset=4
     (get_local $3)
    )
   )
@@ -544,7 +541,7 @@
      )
     )
     (set_local $4
-     (i32.load16_u
+     (i32.load16_u offset=4
       (tee_local $3
        (i32.add
         (get_local $3)
@@ -580,7 +577,7 @@
       )
      )
      (set_local $4
-      (i32.load16_u
+      (i32.load16_u offset=4
        (tee_local $3
         (i32.add
          (get_local $3)
@@ -632,7 +629,7 @@
           (block $case1|0
            (block $case0|0
             (set_local $6
-             (i32.load16_u
+             (i32.load16_u offset=4
               (i32.add
                (get_local $3)
                (i32.const 2)
@@ -739,6 +736,31 @@
      (i32.const 10)
     )
    )
+   (if
+    (i32.and
+     (if (result i32)
+      (i32.ne
+       (i32.lt_s
+        (get_local $1)
+        (i32.const 2)
+       )
+       (i32.const 0)
+      )
+      (i32.lt_s
+       (get_local $1)
+       (i32.const 2)
+      )
+      (i32.gt_s
+       (get_local $1)
+       (i32.const 36)
+      )
+     )
+     (i32.const 1)
+    )
+    (return
+     (i64.const 0)
+    )
+   )
   )
   (set_local $7
    (i64.const 0)
@@ -761,7 +783,7 @@
      (block
       (block
        (set_local $4
-        (i32.load16_u
+        (i32.load16_u offset=4
          (get_local $3)
         )
        )