diff --git a/lib/less/source-map-output.js b/lib/less/source-map-output.js
index 45331829..35abd5a6 100644
--- a/lib/less/source-map-output.js
+++ b/lib/less/source-map-output.js
@@ -32,8 +32,12 @@
         lines = chunk.split("\n");
         columns = lines[lines.length-1];
 
-        this._lineNumber += lines.length - 1;
-        this._column += columns.length - 1;
+        if (lines.length === 1) {
+            this._column += columns.length;
+        } else {
+            this._lineNumber += lines.length - 1;
+            this._column = columns.length;
+        }
 
         this._css.push(chunk);
     };
diff --git a/test/less/sourcemaps/basic.less b/test/less/sourcemaps/basic.less
index b064c722..a3f4bbc5 100644
--- a/test/less/sourcemaps/basic.less
+++ b/test/less/sourcemaps/basic.less
@@ -1,3 +1,5 @@
+@var: black;
+
 .a() {
   color: red;
 }
@@ -6,4 +8,19 @@
   color: green;
   .a();
   color: blue;
+  background: @var;
+}
+
+.a, .b {
+  background: green;
+  .c, .d {
+    background: gray;
+    & + & {
+      color: red;
+    }
+  }
+}
+
+.extend:extend(.a all) {
+  color: pink;
 }
\ No newline at end of file
diff --git a/test/sourcemaps/basic.json b/test/sourcemaps/basic.json
index 415d3e5a..8d678657 100644
--- a/test/sourcemaps/basic.json
+++ b/test/sourcemaps/basic.json
@@ -1 +1 @@
-{"version":3,"file":"basic.css","sources":["basic.less"],"names":[],"mappings":"EAIE,UAAA;aAJA,QAAA;sBAMA,SAAA","sourceRoot":""}
\ No newline at end of file
+{"version":3,"file":"sourcemaps/basic.css","sources":["sourcemaps/basic.less"],"names":[],"mappings":"AAMG;EACD,YAAA;EAJA,UAAA;EAWA,iBAAA;EALA,WAAA;EACA,mBAAA;;AAJC,EASC;AATD,EASM;EACL,gBAAA;;AACE,EAFF,GAEM,KAFN;AAEE,EAFF,GAEM,KAFD;AAEH,EAFG,GAEC,KAFN;AAEE,EAFG,GAEC,KAFD;EAGH,UAAA;;AALJ;AAAK;AAUA;EATL,iBAAA;;AADA,EAEE;AAFG,EAEH;AAFF,EAEO;AAFF,EAEE;AAQF,OARH;AAQG,OARE;EACL,gBAAA;;AACE,EAFF,GAEM,KAFN;AAEE,EAFF,GAEM,KAFN;AAEE,EAFF,GAEM,KAFD;AAEH,EAFF,GAEM,KAFD;AAEH,EAFF,GAEM,KAFN;AAEE,EAFF,GAEM,KAFN;AAEE,EAFF,GAEM,KAFD;AAEH,EAFF,GAEM,KAFD;AAEH,EAFG,GAEC,KAFN;AAEE,EAFG,GAEC,KAFN;AAEE,EAFG,GAEC,KAFD;AAEH,EAFG,GAEC,KAFD;AAEH,EAFG,GAEC,KAFN;AAEE,EAFG,GAEC,KAFN;AAEE,EAFG,GAEC,KAFD;AAEH,EAFG,GAEC,KAFD;AAQF,OARH,GAQG,UARH;AAQG,OARH,GAEM,KAFN;AAQG,OARH,GAQG,UARE;AAQF,OARH,GAEM,KAFD;AAEH,EAFF,GAQG,UARH;AAEE,EAFF,GAQG,UARE;AAQF,OARE,GAQF,UARH;AAQG,OARE,GAEC,KAFN;AAQG,OARE,GAQF,UARE;AAQF,OARE,GAEC,KAFD;AAEH,EAFG,GAQF,UARH;AAEE,EAFG,GAQF,UARE;EAGH,UAAA;;AAKC;EACL,WAAA,"sourceRoot":""}
\ No newline at end of file