diff --git a/Library/Contributions/manpages/brew.1.md b/Library/Contributions/manpages/brew.1.md
index cf4fec4a3b..b5184d055f 100644
--- a/Library/Contributions/manpages/brew.1.md
+++ b/Library/Contributions/manpages/brew.1.md
@@ -146,6 +146,15 @@ didn't include with OS X.
   * HOMEBREW\_DEBUG:
     If set, instructs Homebrew to always assume `--debug` when running commands.
 
+  * HOMEBREW\_TEMP:
+    If set, instructs Homebrew to use `HOMEBREW_TEMP` as the temporary folder
+    for building packages. This may be needed if your system temp folder and
+    Homebrew Prefix are on different volumes, as OS X has trouble moving
+    symlinks across volumes when the target does not yet exist.
+
+    This issue typically occurs when using FileVault (or certain custom SSD
+    configurations.)
+
   * HOMEBREW\_USE\_LLVM:
     If set, instructs Homebrew to use the LLVM front-ends to the GCC compilers.  
     *NOTE*: Not all formulae will build correctly under LLVM.
diff --git a/Library/Homebrew/brew_doctor.rb b/Library/Homebrew/brew_doctor.rb
index e6202798c1..c4daa06c46 100644
--- a/Library/Homebrew/brew_doctor.rb
+++ b/Library/Homebrew/brew_doctor.rb
@@ -353,17 +353,13 @@ def check_for_multiple_volumes
 
   unless where_cellar == where_temp
     puts <<-EOS.undent
-      Your Cellar and TMP folders are on different volumes.
+      Your Cellar and /tmp folders are on different volumes.
 
       Putting your Cellar and TMP folders on different volumes causes problems
       for brews that install symlinks, such as Git.
 
-      Please post the details of your setup to this existing issue, if the comments
-      there don't already capture them:
-        http://github.com/mxcl/homebrew/issues/issue/1238
-
-      A work-around is available in this branch:
-        http://github.com/adamv/homebrew/tree/temp
+      You should set the "HOMEBREW_TEMP" environmental variable to a suitable
+      folder on the same volume as your Cellar.
 
     EOS
   end
diff --git a/Library/Homebrew/formula.rb b/Library/Homebrew/formula.rb
index 7f8b5ebc53..325ec8408c 100644
--- a/Library/Homebrew/formula.rb
+++ b/Library/Homebrew/formula.rb
@@ -347,7 +347,12 @@ private
     # I used /tmp rather than mktemp -td because that generates a directory
     # name with exotic characters like + in it, and these break badly written
     # scripts that don't escape strings before trying to regexp them :(
-    tmp=Pathname.new `/usr/bin/mktemp -d /tmp/homebrew-#{name}-#{version}-XXXX`.strip
+
+    # If the user has FileVault enabled, then we can't mv symlinks from the
+    # /tmp volume to the other volume. So we let the user override the tmp
+    # prefix if they need to.
+    tmp_prefix = ENV['HOMEBREW_TEMP'] || '/tmp'
+    tmp=Pathname.new `/usr/bin/mktemp -d #{tmp_prefix}/homebrew-#{name}-#{version}-XXXX`.strip
     raise "Couldn't create build sandbox" if not tmp.directory? or $? != 0
     begin
       wd=Dir.pwd
diff --git a/share/man/man1/brew.1 b/share/man/man1/brew.1
index 7c4ff5c147..e286e430c4 100644
--- a/share/man/man1/brew.1
+++ b/share/man/man1/brew.1
@@ -1,7 +1,7 @@
 .\" generated with Ronn/v0.7.3
 .\" http://github.com/rtomayko/ronn/tree/0.7.3
 .
-.TH "BREW" "1" "June 2010" "Homebrew" "brew"
+.TH "BREW" "1" "July 2010" "Homebrew" "brew"
 .
 .SH "NAME"
 \fBbrew\fR \- The missing package manager for OS X
@@ -161,6 +161,13 @@ HOMEBREW_DEBUG
 If set, instructs Homebrew to always assume \fB\-\-debug\fR when running commands\.
 .
 .TP
+HOMEBREW_TEMP
+If set, instructs Homebrew to use \fBHOMEBREW_TEMP\fR as the temporary folder for building packages\. This may be needed if your system temp folder and Homebrew Prefix are on different volumes, as OS X has trouble moving symlinks across volumes when the target does not yet exist\.
+.
+.IP
+This issue typically occurs when using FileVault (or certain custom SSD configurations\.)
+.
+.TP
 HOMEBREW_USE_LLVM
 If set, instructs Homebrew to use the LLVM front\-ends to the GCC compilers\.
 .