Index: lib/Driver/ToolChains.cpp
===================================================================
--- lib/Driver/ToolChains.cpp
+++ lib/Driver/ToolChains.cpp
@@ -2319,7 +2319,7 @@
   switch (Triple.getArch()) {
   case llvm::Triple::x86: {
     file_paths.push_back(FilePath + "x86_64-nacl/lib32");
-    file_paths.push_back(FilePath + "x86_64-nacl/usr/lib32");
+    file_paths.push_back(FilePath + "i686-nacl/usr/lib");
     prog_paths.push_back(ProgPath + "x86_64-nacl/bin");
     file_paths.push_back(ToolPath + "i686-nacl");
     break;
@@ -2371,12 +2371,21 @@
 
   SmallString<128> P(D.Dir + "/../");
   switch (getTriple().getArch()) {
+  case llvm::Triple::x86:
+    // x86 is special because multilib style uses x86_64-nacl/include for libc
+    // headers but the SDK wants i686-nacl/usr/include. The other architectures
+    // have the same substring.
+    llvm::sys::path::append(P, "i686-nacl/usr/include");
+    addSystemInclude(DriverArgs, CC1Args, P.str());
+    llvm::sys::path::remove_filename(P);
+    llvm::sys::path::remove_filename(P);
+    llvm::sys::path::remove_filename(P);
+    llvm::sys::path::append(P, "x86_64-nacl/include");
+    addSystemInclude(DriverArgs, CC1Args, P.str());
+    return;
   case llvm::Triple::arm:
     llvm::sys::path::append(P, "arm-nacl/usr/include");
     break;
-  case llvm::Triple::x86:
-    llvm::sys::path::append(P, "x86_64-nacl/usr/include");
-    break;
   case llvm::Triple::x86_64:
     llvm::sys::path::append(P, "x86_64-nacl/usr/include");
     break;
Index: test/Driver/nacl-direct.c
===================================================================
--- test/Driver/nacl-direct.c
+++ test/Driver/nacl-direct.c
@@ -9,7 +9,7 @@
 // CHECK-I686: "-target-cpu" "pentium4"
 // CHECK-I686: "-resource-dir" "foo"
 // CHECK-I686: "-internal-isystem" "foo{{/|\\\\}}include"
-// CHECK-I686: "-internal-isystem" "{{.*}}{{/|\\\\}}..{{/|\\\\}}x86_64-nacl{{/|\\\\}}usr{{/|\\\\}}include"
+// CHECK-I686: "-internal-isystem" "{{.*}}{{/|\\\\}}..{{/|\\\\}}i686-nacl{{/|\\\\}}usr{{/|\\\\}}include"
 // CHECK-I686: "-internal-isystem" "{{.*}}{{/|\\\\}}..{{/|\\\\}}x86_64-nacl{{/|\\\\}}include"
 // CHECK-I686: as{{(.exe)?}}" "--32"
 // CHECK-I686: ld{{(.exe)?}}"
@@ -17,7 +17,7 @@
 // CHECK-I686: "-m" "elf_i386_nacl"
 // CHECK-I686: "-static"
 // CHECK-I686: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}x86_64-nacl{{/|\\\\}}lib32"
-// CHECK-I686: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}x86_64-nacl{{/|\\\\}}usr{{/|\\\\}}lib32"
+// CHECK-I686: "-L{{.*}}{{/|\\\\}}..{{/|\\\\}}i686-nacl{{/|\\\\}}usr{{/|\\\\}}lib"
 // CHECK-I686: "-Lfoo{{/|\\\\}}lib{{/|\\\\}}i686-nacl"
 // CHECK-I686-NOT: -lpthread
 //
@@ -118,7 +118,7 @@
 // CHECK-I686-CXX: "-resource-dir" "foo"
 // CHECK-I686-CXX: "-internal-isystem" "{{.*}}{{/|\\\\}}..{{/|\\\\}}x86_64-nacl{{/|\\\\}}include{{/|\\\\}}c++{{/|\\\\}}v1"
 // CHECK-I686-CXX: "-internal-isystem" "foo{{/|\\\\}}include"
-// CHECK-I686-CXX: "-internal-isystem" "{{.*}}{{/|\\\\}}..{{/|\\\\}}x86_64-nacl{{/|\\\\}}usr{{/|\\\\}}include"
+// CHECK-I686-CXX: "-internal-isystem" "{{.*}}{{/|\\\\}}..{{/|\\\\}}i686-nacl{{/|\\\\}}usr{{/|\\\\}}include"
 // CHECK-I686-CXX: "-internal-isystem" "{{.*}}{{/|\\\\}}..{{/|\\\\}}x86_64-nacl{{/|\\\\}}include"
 // CHECK-I686-CXX: "-lpthread"