diff --git a/src/renderer.js b/src/renderer.js
index 266feb1..af8c3f5 100644
--- a/src/renderer.js
+++ b/src/renderer.js
@@ -17,7 +17,6 @@ module.exports = (config) => {
     while ((match = /```/m.exec(data.slice(i)))) {
       parts.push({
         index: i,
-        end: i + match.index,
         text: data.slice(i, i + match.index),
       });
       i += match.index + match[0].length;
@@ -25,7 +24,6 @@ module.exports = (config) => {
     if (i < data.length)
       parts.push({
         index: i,
-        end: data.length,
         text: data.slice(i, data.length),
       });
 
@@ -38,7 +36,6 @@ module.exports = (config) => {
       while ((match = /(<script>((?:(?!<\/script>)[\s\S])*)<\/script>)/gm.exec(p.text.slice(i)))) {
         subParts.push({
           index: p.index + i,
-          end: i + match.index,
           text: p.text.slice(i, i + match.index),
         });
         i += match.index + match[0].length;
@@ -46,11 +43,13 @@ module.exports = (config) => {
       if (i < p.text.length)
         subParts.push({
           index: p.index + i,
-          end: p.text.length,
           text: p.text.slice(i, p.text.length),
         });
       parts.splice(pi, 1, ...subParts);
     });
+
+    parts.forEach(part => part.end = part.index + part.text.length);
+
     return parts;
   };
 
@@ -139,7 +138,7 @@ module.exports = (config) => {
     const eqRegex = /\$\$((?:(?!\$\$)[\s\S])*)\$\$/m;
     const inlineEqRegex = /\$([^$\n]*)\$/;
 
-    for (let i = 0; i < parts.length; i += 2) {
+    for (let i = 0; i < parts.length; i++) {
       let match;
       if ((match = eqRegex.exec(parts[i].text))) {
         return doMJ(match, 'TeX', i);
diff --git a/test/renderer.test.js b/test/renderer.test.js
index b4324a4..16addbe 100644
--- a/test/renderer.test.js
+++ b/test/renderer.test.js
@@ -55,8 +55,32 @@ describe('get parts', () => {
   test('lot of stuff', () => {
     const data = 'Hello\nthere\n```code```\ngeneral<script>script</script>\n<script>script2</script>\n```<script>script3</script>```kenobi';
     const parts = renderer.getParts(data);
-    expect(parts.map(p => p.text)).toEqual([
-      'Hello\nthere\n', '\ngeneral', '\n', '\n', 'kenobi'
+    expect(parts).toEqual([
+      {
+        index: 0,
+        end: 12,
+        text: 'Hello\nthere\n'
+      },
+      {
+        index: 22,
+        end: 30,
+        text: '\ngeneral'
+      },
+      {
+        index: 53,
+        end: 54,
+        text: '\n'
+      },
+      {
+        index: 78,
+        end: 79,
+        text: '\n'
+      },
+      {
+        index: 109,
+        end: 115,
+        text: 'kenobi'
+      },
     ]);
   });
 });
@@ -132,8 +156,8 @@ describe('Test PlantUML', () => {
   });
 
   test('plantuml ignored in code', (done) => {
-    renderer.renderPlantUML('code:\n```@startuml\nBob -> Alice : hello\n@enduml```', (data) => {
-      expect(data).toBe('code:\n```@startuml\nBob -> Alice : hello\n@enduml```');
+    renderer.renderPlantUML('code:\n```@startuml\nBob -> Alice : hello\n@enduml```\n ```@startuml``` @enduml', (data) => {
+      expect(data).toBe('code:\n```@startuml\nBob -> Alice : hello\n@enduml```\n ```@startuml``` @enduml');
       done();
     });
   });
@@ -183,9 +207,9 @@ describe('Test MathJax', () => {
       done();
     });
   });
-  test('no eq in code', (done) => {
-    renderer.renderMathJax('this code is ```start $a$ end $$hello$$``` beautiful', (data) => {
-      expect(data).toBe('this code is ```start $a$ end $$hello$$``` beautiful');
+  test('no eq in code / script', (done) => {
+    renderer.renderMathJax('this code is ```start $a$ end $$hello$$``` beautiful <script>$A$</script>\n```$no eq$```', (data) => {
+      expect(data).toBe('this code is ```start $a$ end $$hello$$``` beautiful <script>$A$</script>\n```$no eq$```');
       done();
     });
   });