diff --git a/debian/changelog b/debian/changelog
index 42fde0f0..41197542 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,6 +1,8 @@
 llvm-toolchain-4.0 (1:4.0.1-2) unstable; urgency=medium
 
   * Rebuild with gcc 7 to fix a relocation error (Closes: #866354)
+  * Also add a missing include in ftfbs-gcc.diff to fix a ftbfs
+    with gcc 7
   * ld.lld manpage wasn't installed
   * Link LLDB with -latomic on powerpcspe (Closes: #872267)
   * Disable -gsplit-dwarf when using gcc 7 for causing a linking issue
diff --git a/debian/patches/ftfbs-gcc.diff b/debian/patches/ftfbs-gcc.diff
new file mode 100644
index 00000000..f89ce4f9
--- /dev/null
+++ b/debian/patches/ftfbs-gcc.diff
@@ -0,0 +1,12 @@
+Index: llvm-toolchain-4.0-4.0.1~+rc3/lldb/include/lldb/Utility/TaskPool.h
+===================================================================
+--- llvm-toolchain-4.0-4.0.1~+rc3.orig/lldb/include/lldb/Utility/TaskPool.h
++++ llvm-toolchain-4.0-4.0.1~+rc3/lldb/include/lldb/Utility/TaskPool.h
+@@ -33,6 +33,7 @@
+ #include <queue>
+ #include <thread>
+ #include <vector>
++#include <functional>
+ 
+ // Global TaskPool class for running tasks in parallel on a set of worker thread
+ // created the first
diff --git a/debian/patches/series b/debian/patches/series
index 0af13e9e..6fdb4a3f 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -46,3 +46,4 @@ silent-test-failing-codeverage.diff
 silent-amdgpu-test-failing.diff
 pthread-link.diff
 add_symbols_versioning.patch
+ftfbs-gcc.diff