diff --git a/debian/changelog b/debian/changelog
index f6fa330b..f180c750 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -5,6 +5,7 @@ llvm-toolchain-3.4 (1:3.4.2-6) unstable; urgency=medium
   * Move the polly installation in the dh_auto_install rules instead
     of using *.install files. In llvm.org/apt/, I have to sometime disable
     polly
+  * hurd-EIEIO-undef.diff: try to undef an errno.h to fix the ftbfs
 
  -- Sylvestre Ledru <sylvestre@debian.org>  Wed, 23 Jul 2014 13:02:56 +0200
 
diff --git a/debian/patches/hurd-EIEIO-undef.diff b/debian/patches/hurd-EIEIO-undef.diff
new file mode 100644
index 00000000..02f409e8
--- /dev/null
+++ b/debian/patches/hurd-EIEIO-undef.diff
@@ -0,0 +1,14 @@
+Index: llvm-toolchain-3.4-3.4.2/utils/TableGen/InstrInfoEmitter.cpp
+===================================================================
+--- llvm-toolchain-3.4-3.4.2.orig/utils/TableGen/InstrInfoEmitter.cpp
++++ llvm-toolchain-3.4-3.4.2/utils/TableGen/InstrInfoEmitter.cpp
+@@ -569,6 +569,9 @@ void InstrInfoEmitter::emitEnums(raw_ost
+   OS << "\n#ifdef GET_INSTRINFO_ENUM\n";
+   OS << "#undef GET_INSTRINFO_ENUM\n";
+ 
++  OS << "// Undef for HURD\n";
++  OS << "#ifdef EIEIO\n#undef EIEIO\n#endif\n";
++
+   OS << "namespace llvm {\n\n";
+ 
+   CodeGenTarget Target(Records);
diff --git a/debian/patches/series b/debian/patches/series
index 0e24072b..2d629e96 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -42,3 +42,4 @@ CVE-2014-2893.diff
 follow-parallel-var.diff
 scan-build-search-path.diff
 gcc-4.9-i586-linux-gnu.diff
+hurd-EIEIO-undef.diff