diff --git a/lib/parser.js b/lib/parser.js
index f775c56..88599c7 100644
--- a/lib/parser.js
+++ b/lib/parser.js
@@ -1,119 +1,103 @@
-const Parsimmon = require('parsimmon');
+const bnb = require('bread-n-butter');
 
 function makeNode(type) {
   return function makeNodeWrapper(parser) {
-    return Parsimmon.seqMap(
-      Parsimmon.index,
-      parser,
-      Parsimmon.index,
-      function makeNode_(start, value, end) {
+    return bnb
+      .all(bnb.location, parser, bnb.location)
+      .map(function makeNode_([start, value, end]) {
         return {
           type,
-          start: start.offset,
-          end: end.offset,
+          start: start.index,
+          end: end.index,
+          // @ts-ignore
           ...value,
         };
-      }
-    );
+      });
   };
 }
 
-const Lang = Parsimmon.createLanguage({
-  Program: (r) =>
-    Parsimmon.alt(
-      r.Superscript,
-      r.Subscript,
-      r.UnaryMacro,
-      r.NullaryMacro,
-      r.Illegal,
-      r.PlainText
-    )
-      .many()
-      .map((nodes) => {
-        return {
-          body: nodes,
-        };
-      })
-      .thru(makeNode('Program')),
+const Spaces = bnb.match(/\s*/);
 
-  Superscript: () =>
-    Parsimmon.seq(
-      Parsimmon.regexp(/\^\s*/),
-      Parsimmon.alt(
-        Parsimmon.regexp(/{[a-zA-Z0-9+-]+}/),
-        Parsimmon.regexp(/[a-zA-Z0-9+-]/)
-      )
-    )
-      .map(([, b]) => ({
-        content: b,
-      }))
-      .thru(makeNode('Superscript')),
+const Superscript = bnb
+  .all(
+    bnb.match(/\^\s*/),
+    bnb.choice(bnb.match(/{[a-zA-Z0-9+-]+}/), bnb.match(/[a-zA-Z0-9+-]/))
+  )
+  .map(([, b]) => ({
+    content: b,
+  }))
+  .thru(makeNode('Superscript'));
 
-  Subscript: () =>
-    Parsimmon.seq(
-      Parsimmon.regexp(/_\s*/),
-      Parsimmon.alt(
-        Parsimmon.regexp(/{[a-zA-Z0-9+-]+}/),
-        Parsimmon.regexp(/[a-zA-Z0-9+-]/)
-      )
-    )
-      .map(([_, b]) => {
-        return {
-          content: b,
-        };
-      })
-      .thru(makeNode('Subscript')),
+const Subscript = bnb
+  .all(
+    bnb.match(/_\s*/),
+    bnb.choice(bnb.match(/{[a-zA-Z0-9+-]+}/), bnb.match(/[a-zA-Z0-9+-]/))
+  )
+  .map(([_, b]) => {
+    return {
+      content: b,
+    };
+  })
+  .thru(makeNode('Subscript'));
 
-  UnaryMacro: (r) =>
-    Parsimmon.seq(
-      Parsimmon.alt(
-        Parsimmon.regexp(/\\mathbb(?![a-zA-Z])/),
-        Parsimmon.regexp(/\\mathfrak(?![a-zA-Z])/),
-        Parsimmon.regexp(/\\mathcal(?![a-zA-Z])/),
-        Parsimmon.regexp(/\\not(?![a-zA-Z])/)
-      ),
-      r._,
-      Parsimmon.alt(
-        r.CurlyGroup,
-        r.NullaryMacro,
-        Parsimmon.regexp(/[a-zA-Z0-9]/)
-          .map((x) => ({value: x}))
-          .thru(makeNode('PlainText'))
-      )
-    )
-      .map(([a, _, c]) => ({
-        macro: a,
-        argument: c,
-      }))
-      .thru(makeNode('UnaryMacro')),
+const NullaryMacro = bnb
+  .choice(bnb.match(/\\[a-zA-Z]+/), bnb.match(/\\\|/))
+  .map((x) => {
+    return {
+      macro: x,
+    };
+  })
+  .thru(makeNode('NullaryMacro'));
 
-  NullaryMacro: () =>
-    Parsimmon.alt(Parsimmon.regexp(/\\[a-zA-Z]+/), Parsimmon.regexp(/\\\|/))
-      .map((x) => {
-        return {
-          macro: x,
-        };
-      })
-      .thru(makeNode('NullaryMacro')),
+const CurlyGroup = bnb
+  .match(/\{.*?\}/)
+  .map((x) => ({value: x}))
+  .thru(makeNode('CurlyGroup'));
 
-  Illegal: () =>
-    Parsimmon.regexp(/[\^_\\]/)
-      .map((r) => ({
-        value: r,
-      }))
-      .thru(makeNode('PlainText')),
+const UnaryMacro = bnb
+  .all(
+    bnb.choice(
+      bnb.match(/\\mathbb(?![a-zA-Z])/),
+      bnb.match(/\\mathfrak(?![a-zA-Z])/),
+      bnb.match(/\\mathcal(?![a-zA-Z])/),
+      bnb.match(/\\not(?![a-zA-Z])/)
+    ),
+    Spaces,
+    bnb.choice(
+      CurlyGroup,
+      NullaryMacro,
+      bnb
+        .match(/[a-zA-Z0-9]/)
+        .map((x) => ({value: x}))
+        .thru(makeNode('PlainText'))
+    )
+  )
+  .map(([a, _, c]) => ({
+    macro: a,
+    argument: c,
+  }))
+  .thru(makeNode('UnaryMacro'));
 
-  PlainText: () =>
-    Parsimmon.regexp(/[^_^\\]+/)
-      .map((x) => ({value: x}))
-      .thru(makeNode('PlainText')),
+const Illegal = bnb
+  .match(/[\^_\\]/)
+  .map((r) => ({
+    value: r,
+  }))
+  .thru(makeNode('PlainText'));
 
-  CurlyGroup: () =>
-    Parsimmon.regexp(/\{.*?\}/)
-      .map((x) => ({value: x}))
-      .thru(makeNode('CurlyGroup')),
+const PlainText = bnb
+  .match(/[^_^\\]+/)
+  .map((x) => ({value: x}))
+  .thru(makeNode('PlainText'));
 
-  _: () => Parsimmon.regexp(/\s*/),
-});
+const Program = bnb
+  .choice(Superscript, Subscript, UnaryMacro, NullaryMacro, Illegal, PlainText)
+  .repeat()
+  .map((nodes) => {
+    return {
+      body: nodes,
+    };
+  })
+  .thru(makeNode('Program'));
 
-module.exports = Lang.Program;
+module.exports = Program;
diff --git a/package-lock.json b/package-lock.json
index 0fa5090..a46e9bd 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -7,7 +7,7 @@
       "name": "tex-to-unicode",
       "license": "MIT",
       "dependencies": {
-        "parsimmon": "^1.12.0"
+        "bread-n-butter": "^0.6.0"
       },
       "devDependencies": {
         "@types/chrome": "^0.0.176",
@@ -1783,6 +1783,11 @@
         "node": ">=8"
       }
     },
+    "node_modules/bread-n-butter": {
+      "version": "0.6.0",
+      "resolved": "https://registry.npmjs.org/bread-n-butter/-/bread-n-butter-0.6.0.tgz",
+      "integrity": "sha512-ATCbBoEdO7LPmFPCfO1dz8jgFEsOIlMx4hDPd4NtX42gJXNC7er8vK45jHlUmC1Ok/1I+VuZ6VZNbU+WipxR6Q=="
+    },
     "node_modules/browser-process-hrtime": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/browser-process-hrtime/-/browser-process-hrtime-1.0.0.tgz",
@@ -4470,11 +4475,6 @@
       "integrity": "sha512-Ofn/CTFzRGTTxwpNEs9PP93gXShHcTq255nzRYSKe8AkVpZY7e1fpmTfOyoIvjP5HG7Z2ZM7VS9PPhQGW2pOpw==",
       "dev": true
     },
-    "node_modules/parsimmon": {
-      "version": "1.18.1",
-      "resolved": "https://registry.npmjs.org/parsimmon/-/parsimmon-1.18.1.tgz",
-      "integrity": "sha512-u7p959wLfGAhJpSDJVYXoyMCXWYwHia78HhRBWqk7AIbxdmlrfdp5wX0l3xv/iTSH5HvhN9K7o26hwwpgS5Nmw=="
-    },
     "node_modules/path-exists": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/path-exists/-/path-exists-4.0.0.tgz",
@@ -7276,6 +7276,11 @@
         "fill-range": "^7.0.1"
       }
     },
+    "bread-n-butter": {
+      "version": "0.6.0",
+      "resolved": "https://registry.npmjs.org/bread-n-butter/-/bread-n-butter-0.6.0.tgz",
+      "integrity": "sha512-ATCbBoEdO7LPmFPCfO1dz8jgFEsOIlMx4hDPd4NtX42gJXNC7er8vK45jHlUmC1Ok/1I+VuZ6VZNbU+WipxR6Q=="
+    },
     "browser-process-hrtime": {
       "version": "1.0.0",
       "resolved": "https://registry.npmjs.org/browser-process-hrtime/-/browser-process-hrtime-1.0.0.tgz",
@@ -9337,11 +9342,6 @@
       "integrity": "sha512-Ofn/CTFzRGTTxwpNEs9PP93gXShHcTq255nzRYSKe8AkVpZY7e1fpmTfOyoIvjP5HG7Z2ZM7VS9PPhQGW2pOpw==",
       "dev": true
     },
-    "parsimmon": {
-      "version": "1.18.1",
-      "resolved": "https://registry.npmjs.org/parsimmon/-/parsimmon-1.18.1.tgz",
-      "integrity": "sha512-u7p959wLfGAhJpSDJVYXoyMCXWYwHia78HhRBWqk7AIbxdmlrfdp5wX0l3xv/iTSH5HvhN9K7o26hwwpgS5Nmw=="
-    },
     "path-exists": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/path-exists/-/path-exists-4.0.0.tgz",
diff --git a/package.json b/package.json
index 740f755..c8c0b71 100644
--- a/package.json
+++ b/package.json
@@ -19,7 +19,7 @@
     "ci": "npm run prettier && npm run lint && npm run tsc && npm run test"
   },
   "dependencies": {
-    "parsimmon": "^1.12.0"
+    "bread-n-butter": "^0.6.0"
   },
   "devDependencies": {
     "@types/chrome": "^0.0.176",
diff --git a/test/index.spec.js b/test/index.spec.js
index 01e421c..9b0bc7a 100644
--- a/test/index.spec.js
+++ b/test/index.spec.js
@@ -101,7 +101,7 @@ describe('convertText', () => {
 
 describe('Parser', () => {
   test('Should successfully parse \\\\^^__', () => {
-    expect(parser.parse('\\\\^^__').status).toEqual(true);
+    expect(parser.parse('\\\\^^__').type).toEqual('ParseOK');
   });
 });