Index: lib/Driver/ToolChains/Gnu.cpp
===================================================================
--- lib/Driver/ToolChains/Gnu.cpp
+++ lib/Driver/ToolChains/Gnu.cpp
@@ -40,7 +40,13 @@
   // Don't forward inputs from the original command line.  They are added from
   // InputInfoList.
   return O.getKind() != Option::InputClass &&
-         !O.hasFlag(options::DriverOption) && !O.hasFlag(options::LinkerInput);
+         !O.hasFlag(options::DriverOption) &&
+         !O.hasFlag(options::LinkerInput) &&
+         // Filter out -mno-unaligned-access since GCC expects -mstrict-align
+         // instead for some targets and this flag shouldn't effect assembly
+         // or link steps.
+         O.getID() != options::OPT_munaligned_access &&
+         O.getID() != options::OPT_mno_unaligned_access;
 }
 
 // Switch CPU names not recognized by GNU assembler to a close CPU that it does
Index: test/Driver/gcc_forward.c
===================================================================
--- test/Driver/gcc_forward.c
+++ test/Driver/gcc_forward.c
@@ -34,3 +34,11 @@
 // RUN:   | FileCheck --check-prefix=CHECK-ASM %s
 // CHECK-ASM: as
 // CHECK-ASM-NOT: "-g"
+
+// Check that we're not forwarding -mno-unaligned-access since GCC expects
+// -mstrict-align instead for some targets and this flag shouldn't effect
+// linking.
+// RUN: %clang -target aarch64-none-elf -mno-unaligned-access %s -### 2>&1 \
+// RUN:   | FileCheck --check-prefix=CHECK-ARM %s
+// CHECK-ARM: gcc{{[^"]*}}"
+// CHECK-ARM-NOT: -mno-unaligned-access