diff --git a/mode/julia/julia.js b/mode/julia/julia.js
index 5873d8ca95..547669afbc 100644
--- a/mode/julia/julia.js
+++ b/mode/julia/julia.js
@@ -187,15 +187,13 @@ CodeMirror.defineMode("julia", function(config, parserConf) {
       var imMatcher = RegExp(/^im\b/);
       var numberLiteral = false;
       // Floats
-      if (stream.match(/^\d*\.(?!\.)\d*([Eef][\+\-]?\d+)?/i)) { numberLiteral = true; }
-      if (stream.match(/^\d+\.(?!\.)\d*/)) { numberLiteral = true; }
-      if (stream.match(/^\.\d+/)) { numberLiteral = true; }
-      if (stream.match(/^0x\.[0-9a-f]+p[\+\-]?\d+/i)) { numberLiteral = true; }
+      if (stream.match(/^(?:(?:\d[_\d]*)?\.(?!\.)(?:\d[_\d]*)?|\d[_\d]*\.(?!\.)(?:\d[_\d]*))?([Eef][\+\-]?[_\d]+)?/i)) { numberLiteral = true; }
+      if (stream.match(/^0x\.[0-9a-f_]+p[\+\-]?[_\d]+/i)) { numberLiteral = true; }
       // Integers
-      if (stream.match(/^0x[0-9a-f]+/i)) { numberLiteral = true; } // Hex
-      if (stream.match(/^0b[01]+/i)) { numberLiteral = true; } // Binary
-      if (stream.match(/^0o[0-7]+/i)) { numberLiteral = true; } // Octal
-      if (stream.match(/^[1-9]\d*(e[\+\-]?\d+)?/)) { numberLiteral = true; } // Decimal
+      if (stream.match(/^0x[0-9a-f_]+/i)) { numberLiteral = true; } // Hex
+      if (stream.match(/^0b[01_]+/i)) { numberLiteral = true; } // Binary
+      if (stream.match(/^0o[0-7_]+/i)) { numberLiteral = true; } // Octal
+      if (stream.match(/^[1-9][_\d]*(e[\+\-]?\d+)?/)) { numberLiteral = true; } // Decimal
       // Zero by itself with no other piece of number.
       if (stream.match(/^0(?![\dx])/i)) { numberLiteral = true; }
       if (numberLiteral) {