diff --git a/lib/coffee-script/command.js b/lib/coffee-script/command.js
index 63d918ce2d..d0081d8dff 100644
--- a/lib/coffee-script/command.js
+++ b/lib/coffee-script/command.js
@@ -458,7 +458,7 @@
 
   mkdirp = function(dir, fn) {
     var mkdirs, mode;
-    mode = 0x1ff & ~process.umask();
+    mode = 0o777 & ~process.umask();
     return (mkdirs = function(p, fn) {
       return fs.exists(p, function(exists) {
         if (exists) {
diff --git a/lib/coffee-script/lexer.js b/lib/coffee-script/lexer.js
index d27a07261f..5bb21270f9 100644
--- a/lib/coffee-script/lexer.js
+++ b/lib/coffee-script/lexer.js
@@ -22,6 +22,7 @@
       this.indebt = 0;
       this.outdebt = 0;
       this.indents = [];
+      this.indentLiteral = '';
       this.ends = [];
       this.tokens = [];
       this.seenFor = false;
@@ -174,7 +175,7 @@
     };
 
     Lexer.prototype.numberToken = function() {
-      var base, lexedLength, match, number, numberValue, ref2, tag;
+      var base, lexedLength, match, number, numberValue, tag;
       if (!(match = NUMBER.exec(this.chunk))) {
         return 0;
       }
@@ -214,9 +215,6 @@
         }
       })();
       numberValue = base != null ? parseInt(number.slice(2), base) : parseFloat(number);
-      if ((ref2 = number.charAt(1)) === 'b' || ref2 === 'o') {
-        number = "0x" + (numberValue.toString(16));
-      }
       tag = numberValue === 2e308 ? 'INFINITY' : 'NUMBER';
       this.token(tag, number, 0, lexedLength);
       return lexedLength;
@@ -408,7 +406,7 @@
     };
 
     Lexer.prototype.lineToken = function() {
-      var diff, indent, match, noNewlines, size;
+      var diff, indent, match, minLiteralLength, newIndentLiteral, noNewlines, size;
       if (!(match = MULTI_DENT.exec(this.chunk))) {
         return 0;
       }
@@ -416,6 +414,20 @@
       this.seenFor = false;
       size = indent.length - 1 - indent.lastIndexOf('\n');
       noNewlines = this.unfinished();
+      newIndentLiteral = size > 0 ? indent.slice(-size) : '';
+      if (!/^(.?)\1*$/.exec(newIndentLiteral)) {
+        this.error('mixed indentation', {
+          offset: indent.length
+        });
+        return indent.length;
+      }
+      minLiteralLength = Math.min(newIndentLiteral.length, this.indentLiteral.length);
+      if (newIndentLiteral.slice(0, minLiteralLength) !== this.indentLiteral.slice(0, minLiteralLength)) {
+        this.error('indentation mismatch', {
+          offset: indent.length
+        });
+        return indent.length;
+      }
       if (size - this.indebt === this.indent) {
         if (noNewlines) {
           this.suppressNewlines();
@@ -432,6 +444,7 @@
         }
         if (!this.tokens.length) {
           this.baseIndent = this.indent = size;
+          this.indentLiteral = newIndentLiteral;
           return indent.length;
         }
         diff = size - this.indent + this.outdebt;
@@ -442,6 +455,7 @@
         });
         this.outdebt = this.indebt = 0;
         this.indent = size;
+        this.indentLiteral = newIndentLiteral;
       } else if (size < this.baseIndent) {
         this.error('missing indentation', {
           offset: indent.length
@@ -488,6 +502,7 @@
         this.token('TERMINATOR', '\n', outdentLength, 0);
       }
       this.indent = decreasedIndent;
+      this.indentLiteral = this.indentLiteral.slice(0, decreasedIndent);
       return this;
     };
 
diff --git a/lib/coffee-script/nodes.js b/lib/coffee-script/nodes.js
index ce8f0f2afe..f5eb07723a 100644
--- a/lib/coffee-script/nodes.js
+++ b/lib/coffee-script/nodes.js
@@ -2516,12 +2516,14 @@
         o.scope.parameter(fragmentsToText(params[i]));
       }
       uniqs = [];
-      this.eachParamName(function(name, node) {
-        if (indexOf.call(uniqs, name) >= 0) {
-          node.error("multiple parameters named " + name);
-        }
-        return uniqs.push(name);
-      });
+      this.eachParamName((function(_this) {
+        return function(name, node) {
+          if (indexOf.call(uniqs, name) >= 0) {
+            node.error("multiple parameters named '" + name + "'");
+          }
+          return uniqs.push(name);
+        };
+      })(this));
       if (!(wasEmpty || this.noReturn)) {
         this.body.makeReturn();
       }