diff --git a/debian/changelog b/debian/changelog
index c0b69a61..70df64dd 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -3,8 +3,9 @@ llvm-toolchain-3.4 (1:3.4.1-4) unstable; urgency=medium
   * Be less permissive when installing lldb. Remove duplication of the install
     of liblldb.so.1
   * Add symlinks lldb-3.4, lldb-platform-3.4 & lldb-gdbserver-3.4 without 3.4
+  * Clang was unusable with libstdc++ from gcc 4.9 (Closes: #744792)
 
- -- Sylvestre Ledru <sylvestre@debian.org>  Sun, 18 May 2014 20:18:19 +0200
+ -- Sylvestre Ledru <sylvestre@debian.org>  Tue, 27 May 2014 15:17:48 +0200
 
 llvm-toolchain-3.4 (1:3.4.1-3) unstable; urgency=medium
 
diff --git a/debian/patches/gcc-4.9-support.diff b/debian/patches/gcc-4.9-support.diff
new file mode 100644
index 00000000..27927189
--- /dev/null
+++ b/debian/patches/gcc-4.9-support.diff
@@ -0,0 +1,36 @@
+Index: llvm-toolchain-snapshot_3.4~svn192346/clang/lib/Headers/stddef.h
+===================================================================
+--- llvm-toolchain-snapshot_3.4~svn192346/clang/lib/Headers/stddef.h	(révision 201728)
++++ llvm-toolchain-snapshot_3.4~svn192346/clang/lib/Headers/stddef.h	(révision 201729)
+@@ -84,6 +84,16 @@
+ #endif
+ #endif
+ 
++#if __STDC_VERSION__ >= 201112L || __cplusplus >= 201103L
++typedef struct {
++  long long __clang_max_align_nonce1
++      __attribute__((__aligned__(__alignof__(long long))));
++  long double __clang_max_align_nonce2
++      __attribute__((__aligned__(__alignof__(long double))));
++} max_align_t;
++#define __CLANG_MAX_ALIGN_T_DEFINED
++#endif
++
+ #define offsetof(t, d) __builtin_offsetof(t, d)
+ 
+ #endif /* __STDDEF_H */
+Index: llvm-toolchain-snapshot_3.4~svn192346/clang/test/Headers/c11.c
+===================================================================
+--- llvm-toolchain-snapshot_3.4~svn192346/clang/test/Headers/c11.c	(révision 201728)
++++ llvm-toolchain-snapshot_3.4~svn192346/clang/test/Headers/c11.c	(révision 201729)
+@@ -22,6 +22,10 @@
+ #define __STDC_WANT_LIB_EXT1__ 1
+ #include <stddef.h>
+ rsize_t x = 0;
++_Static_assert(sizeof(max_align_t) >= sizeof(long long), "");
++_Static_assert(alignof(max_align_t) >= alignof(long long), "");
++_Static_assert(sizeof(max_align_t) >= sizeof(long double), "");
++_Static_assert(alignof(max_align_t) >= alignof(long double), "");
+ 
+ // If we are freestanding, then also check RSIZE_MAX (in a hosted implementation
+ // we will use the host stdint.h, which may not yet have C11 support).
diff --git a/debian/patches/series b/debian/patches/series
index b503ef00..4a118cb6 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -38,3 +38,4 @@ lldb-link-atomic.diff
 fix-llvm-config-obj-src-root.patch
 scan-build-fix-clang-detection.diff
 compiler-rt-path.diff
+gcc-4.9-support.diff