diff --git a/src/libstore/build.cc b/src/libstore/build.cc
index d3184507ce..1870abead4 100644
--- a/src/libstore/build.cc
+++ b/src/libstore/build.cc
@@ -2075,9 +2075,9 @@ void DerivationGoal::initChild()
                     throw SysError("mounting /dev/pts");
                 createSymlink("/dev/pts/ptmx", chrootRootDir + "/dev/ptmx");
 
-		/* Make sure /dev/pts/ptmx is world-writable.  With some
-		   Linux versions, it is created with permissions 0.  */
-		chmod_(chrootRootDir + "/dev/pts/ptmx", 0666);
+                /* Make sure /dev/pts/ptmx is world-writable.  With some
+                   Linux versions, it is created with permissions 0.  */
+                chmod_(chrootRootDir + "/dev/pts/ptmx", 0666);
             }
 
             /* Do the chroot().  Below we do a chdir() to the