diff --git a/spec/parser/javascript/charset_escape_spec.js b/spec/parser/javascript/charset_escape_spec.js
index 434eec7..e739892 100644
--- a/spec/parser/javascript/charset_escape_spec.js
+++ b/spec/parser/javascript/charset_escape_spec.js
@@ -19,7 +19,7 @@ describe('parser/javascript/charset_escape.js', function() {
     '\\W': { label: 'non-word', ordinal: -1 },
     '\\0': { label: 'null', ordinal: 0 },
     '\\012': { label: 'octal: 12', ordinal: 10 },
-    '\\cx': { label: 'ctrl-x', ordinal: -1 },
+    '\\cx': { label: 'ctrl-X', ordinal: 24 },
     '\\xab': { label: '0xAB', ordinal: 0xab },
     '\\uabcd': { label: 'U+ABCD', ordinal: 0xabcd }
   }, (content, str) => {
diff --git a/spec/parser/javascript/escape_spec.js b/spec/parser/javascript/escape_spec.js
index d52dba0..cffcd73 100644
--- a/spec/parser/javascript/escape_spec.js
+++ b/spec/parser/javascript/escape_spec.js
@@ -29,7 +29,7 @@ describe('parser/javascript/escape.js', function() {
     '\\8': { label: 'Back reference (group = 8)', ordinal: -1 },
     '\\9': { label: 'Back reference (group = 9)', ordinal: -1 },
     '\\012': { label: 'octal: 12', ordinal: 10 },
-    '\\cx': { label: 'ctrl-x', ordinal: -1 },
+    '\\cx': { label: 'ctrl-X', ordinal: 24 },
     '\\xab': { label: '0xAB', ordinal: 0xab },
     '\\uabcd': { label: 'U+ABCD', ordinal: 0xabcd }
   }, (content, str) => {
diff --git a/src/js/parser/javascript/escape.js b/src/js/parser/javascript/escape.js
index 47a0340..27eaf8e 100644
--- a/src/js/parser/javascript/escape.js
+++ b/src/js/parser/javascript/escape.js
@@ -50,7 +50,7 @@ export default {
     }
   },
   c() {
-    return [`ctrl-${this.arg}`, -1];
+    return [`ctrl-${this.arg.toUpperCase()}`, this.arg.toUpperCase().charCodeAt(0) - 64];
   },
   x() {
     return [`0x${this.arg.toUpperCase()}`, parseInt(this.arg, 16)];