Index: lib/Basic/Targets.cpp
===================================================================
--- lib/Basic/Targets.cpp
+++ lib/Basic/Targets.cpp
@@ -7577,7 +7577,11 @@
 
   void setN64ABITypes() {
     setN32N64ABITypes();
-    Int64Type = SignedLong;
+    if (getTriple().getOS() == llvm::Triple::OpenBSD) {
+      Int64Type = SignedLongLong;
+    } else {
+      Int64Type = SignedLong;
+    }
     IntMaxType = Int64Type;
     LongWidth = LongAlign = 64;
     PointerWidth = PointerAlign = 64;
Index: test/Preprocessor/init.c
===================================================================
--- test/Preprocessor/init.c
+++ test/Preprocessor/init.c
@@ -8766,6 +8766,8 @@
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=arm-unknown-openbsd6.1-gnueabi < /dev/null | FileCheck -match-full-lines -check-prefix OPENBSD %s
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=i386-unknown-openbsd6.1 < /dev/null | FileCheck -match-full-lines -check-prefix OPENBSD %s
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=powerpc-unknown-openbsd6.1 < /dev/null | FileCheck -match-full-lines -check-prefix OPENBSD %s
+// RUN: %clang_cc1 -E -dM -ffreestanding -triple=mips64-unknown-openbsd6.1 < /dev/null | FileCheck -match-full-lines -check-prefix OPENBSD %s
+// RUN: %clang_cc1 -E -dM -ffreestanding -triple=mips64el-unknown-openbsd6.1 < /dev/null | FileCheck -match-full-lines -check-prefix OPENBSD %s
 // RUN: %clang_cc1 -E -dM -ffreestanding -triple=sparc64-unknown-openbsd6.1 < /dev/null | FileCheck -match-full-lines -check-prefix OPENBSD %s
 // OPENBSD:#define __ELF__ 1
 // OPENBSD:#define __INT16_TYPE__ short