diff --git a/lib/renderer.js b/lib/renderer.js
index 3e742fe..35a49e7 100644
--- a/lib/renderer.js
+++ b/lib/renderer.js
@@ -240,17 +240,11 @@ rules.mark_close = function(/*tokens, idx, options*/) {
 };
 
 
-rules.sub_open = function(/*tokens, idx, options*/) {
-  return '<sub>';
+rules.sub = function(tokens, idx/*, options*/) {
+  return '<sub>' + escapeHtml(tokens[idx].content) + '</sub>';
 };
-rules.sub_close = function(/*tokens, idx, options*/) {
-  return '</sub>';
-};
-rules.sup_open = function(/*tokens, idx, options*/) {
-  return '<sup>';
-};
-rules.sup_close = function(/*tokens, idx, options*/) {
-  return '</sup>';
+rules.sup = function(tokens, idx/*, options*/) {
+  return '<sup>' + escapeHtml(tokens[idx].content) + '</sup>';
 };
 
 
diff --git a/lib/rules_inline/del.js b/lib/rules_inline/del.js
index c34e4dd..1258e56 100644
--- a/lib/rules_inline/del.js
+++ b/lib/rules_inline/del.js
@@ -26,8 +26,8 @@ module.exports = function del(state, silent) {
 
   pos = start + 2;
   while (pos < max && state.src.charCodeAt(pos) === 0x7E/* ~ */) { pos++; }
-  if (pos !== start + 2) {
-    // sequence of 3+ markers taking as literal, same as in a emphasis
+  if (pos > start + 3) {
+    // sequence of 4+ markers taking as literal, same as in a emphasis
     state.pos += pos - start;
     if (!silent) { state.pending += state.src.slice(start, pos); }
     return true;
diff --git a/lib/rules_inline/sub.js b/lib/rules_inline/sub.js
index dd5d8fd..a126e9a 100644
--- a/lib/rules_inline/sub.js
+++ b/lib/rules_inline/sub.js
@@ -2,53 +2,40 @@
 
 'use strict';
 
+// same as UNESCAPE_MD_RE plus a space
+var UNESCAPE_RE = /\\([ \\!"#$%&'()*+,.\/:;<=>?@[\]^_`{|}~-])/g;
+
 module.exports = function sub(state, silent) {
   var found,
-      stack,
+      content,
       max = state.posMax,
-      start = state.pos,
-      lastChar,
-      nextChar;
+      start = state.pos;
 
   if (state.src.charCodeAt(start) !== 0x7E/* ~ */) { return false; }
   if (silent) { return false; } // don't run any pairs in validation mode
   if (start + 2 >= max) { return false; }
   if (state.level >= state.options.maxNesting) { return false; }
 
-  lastChar = start > 0 ? state.src.charCodeAt(start - 1) : -1;
-  nextChar = state.src.charCodeAt(start + 2);
-
-  if (nextChar === 0x20 || nextChar === 0x0A) { return false; }
-
   state.pos = start + 1;
-  stack = 1;
 
   while (state.pos < max) {
     if (state.src.charCodeAt(state.pos) === 0x7E/* ~ */) {
-      lastChar = state.src.charCodeAt(state.pos - 1);
-      nextChar = state.pos + 1 < max ? state.src.charCodeAt(state.pos + 1) : -1;
-      if (nextChar !== 0x7E/* ~ */ && lastChar !== 0x7E/* ~ */) {
-        if (lastChar !== 0x20 && lastChar !== 0x0A) {
-          // closing '~'
-          stack--;
-        } else if (nextChar !== 0x20 && nextChar !== 0x0A) {
-          // opening '~'
-          stack++;
-        } // else {
-          //  // standalone ' ~ ' indented with spaces
-          //}
-        if (stack <= 0) {
-          found = true;
-          break;
-        }
-      }
+      found = true;
+      break;
     }
 
     state.parser.skipToken(state);
   }
 
-  if (!found) {
-    // parser failed to find ending tag, so it's not valid emphasis
+  if (!found || start + 1 === state.pos) {
+    state.pos = start;
+    return false;
+  }
+
+  content = state.src.slice(start + 1, state.pos);
+
+  // don't allow unescaped spaces/newlines inside
+  if (content.match(/(^|[^\\])(\\\\)*\s/)) {
     state.pos = start;
     return false;
   }
@@ -58,9 +45,11 @@ module.exports = function sub(state, silent) {
   state.pos = start + 1;
 
   if (!silent) {
-    state.push({ type: 'sub_open', level: state.level++ });
-    state.parser.tokenize(state);
-    state.push({ type: 'sub_close', level: --state.level });
+    state.push({
+      type: 'sub',
+      level: state.level,
+      content: content.replace(UNESCAPE_RE, '$1')
+    });
   }
 
   state.pos = state.posMax + 1;
diff --git a/lib/rules_inline/sup.js b/lib/rules_inline/sup.js
index 79287ae..07bf357 100644
--- a/lib/rules_inline/sup.js
+++ b/lib/rules_inline/sup.js
@@ -1,54 +1,41 @@
-// Process ~superscript~
+// Process ^superscript^
 
 'use strict';
 
+// same as UNESCAPE_MD_RE plus a space
+var UNESCAPE_RE = /\\([ \\!"#$%&'()*+,.\/:;<=>?@[\]^_`{|}~-])/g;
+
 module.exports = function sup(state, silent) {
   var found,
-      stack,
+      content,
       max = state.posMax,
-      start = state.pos,
-      lastChar,
-      nextChar;
+      start = state.pos;
 
   if (state.src.charCodeAt(start) !== 0x5E/* ^ */) { return false; }
   if (silent) { return false; } // don't run any pairs in validation mode
   if (start + 2 >= max) { return false; }
   if (state.level >= state.options.maxNesting) { return false; }
 
-  lastChar = start > 0 ? state.src.charCodeAt(start - 1) : -1;
-  nextChar = state.src.charCodeAt(start + 2);
-
-  if (nextChar === 0x20 || nextChar === 0x0A) { return false; }
-
   state.pos = start + 1;
-  stack = 1;
 
   while (state.pos < max) {
     if (state.src.charCodeAt(state.pos) === 0x5E/* ^ */) {
-      lastChar = state.src.charCodeAt(state.pos - 1);
-      nextChar = state.pos + 1 < max ? state.src.charCodeAt(state.pos + 1) : -1;
-      if (nextChar !== 0x5E/* ^ */ && lastChar !== 0x5E/* ^ */) {
-        if (lastChar !== 0x20 && lastChar !== 0x0A) {
-          // closing '^'
-          stack--;
-        } else if (nextChar !== 0x20 && nextChar !== 0x0A) {
-          // opening '^'
-          stack++;
-        } // else {
-          //  // standalone ' ^ ' indented with spaces
-          //}
-        if (stack <= 0) {
-          found = true;
-          break;
-        }
-      }
+      found = true;
+      break;
     }
 
     state.parser.skipToken(state);
   }
 
-  if (!found) {
-    // parser failed to find ending tag, so it's not valid emphasis
+  if (!found || start + 1 === state.pos) {
+    state.pos = start;
+    return false;
+  }
+
+  content = state.src.slice(start + 1, state.pos);
+
+  // don't allow unescaped spaces/newlines inside
+  if (content.match(/(^|[^\\])(\\\\)*\s/)) {
     state.pos = start;
     return false;
   }
@@ -58,9 +45,11 @@ module.exports = function sup(state, silent) {
   state.pos = start + 1;
 
   if (!silent) {
-    state.push({ type: 'sup_open', level: state.level++ });
-    state.parser.tokenize(state);
-    state.push({ type: 'sup_close', level: --state.level });
+    state.push({
+      type: 'sup',
+      level: state.level,
+      content: content.replace(UNESCAPE_RE, '$1')
+    });
   }
 
   state.pos = state.posMax + 1;
diff --git a/test/fixtures/remarkable/del.txt b/test/fixtures/remarkable/del.txt
index 62792e2..f69c27f 100644
--- a/test/fixtures/remarkable/del.txt
+++ b/test/fixtures/remarkable/del.txt
@@ -4,20 +4,6 @@
 <p><del>Strikeout</del></p>
 .
 
-
-These are not strikeouts, you have to use exactly two "~~":
-.
-x ~~~foo~~~
-
-x ~~foo~~~
-
-x ~~~foo~~
-.
-<p>x ~~~foo~~~</p>
-<p>x ~~foo~~~</p>
-<p>x ~~~foo~~</p>
-.
-
 Strikeouts have the same priority as emphases:
 
 .
diff --git a/test/fixtures/remarkable/sub.txt b/test/fixtures/remarkable/sub.txt
index 53dfbdf..f4c7804 100644
--- a/test/fixtures/remarkable/sub.txt
+++ b/test/fixtures/remarkable/sub.txt
@@ -1,12 +1,36 @@
 
 .
-~foo ~bar~ baz~
+~foo\~
 .
-<p><sub>foo <sub>bar</sub> baz</sub></p>
+<p>~foo~</p>
 .
 
 .
-this ~ is ~ not ~ subscript
+~foo bar~
 .
-<p>this ~ is ~ not ~ subscript</p>
+<p>~foo bar~</p>
+.
+
+.
+~foo\ bar\ baz~
+.
+<p><sub>foo bar baz</sub></p>
+.
+
+.
+~\ foo\ ~
+.
+<p><sub> foo </sub></p>
+.
+
+.
+~foo\\\\\\\ bar~
+.
+<p><sub>foo\\\ bar</sub></p>
+.
+
+.
+~foo\\\\\\ bar~
+.
+<p>~foo\\\ bar~</p>
 .
diff --git a/test/fixtures/remarkable/sup.txt b/test/fixtures/remarkable/sup.txt
index 1984017..1db493f 100644
--- a/test/fixtures/remarkable/sup.txt
+++ b/test/fixtures/remarkable/sup.txt
@@ -1,18 +1,42 @@
 
 .
-^foo ^bar^ baz^
+^test^
 .
-<p><sup>foo <sup>bar</sup> baz</sup></p>
+<p><sup>test</sup></p>
 .
 
 .
-^foo ~bar~ baz^
+^foo\^
 .
-<p><sup>foo <sub>bar</sub> baz</sup></p>
+<p>^foo^</p>
 .
 
 .
-this ^ is ^ not ^ superscript
+2^4 + 3^5
 .
-<p>this ^ is ^ not ^ superscript</p>
+<p>2^4 + 3^5</p>
+.
+
+.
+^foo~bar^baz^bar~foo^
+.
+<p><sup>foo~bar</sup>baz<sup>bar~foo</sup></p>
+.
+
+.
+^\ foo\ ^
+.
+<p><sup> foo </sup></p>
+.
+
+.
+^foo\\\\\\\ bar^
+.
+<p><sup>foo\\\ bar</sup></p>
+.
+
+.
+^foo\\\\\\ bar^
+.
+<p>^foo\\\ bar^</p>
 .