diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCFixupKinds.h b/lib/Target/PowerPC/MCTargetDesc/PPCFixupKinds.h
index 7917f7736ee..709daa4e4bf 100644
--- a/lib/Target/PowerPC/MCTargetDesc/PPCFixupKinds.h
+++ b/lib/Target/PowerPC/MCTargetDesc/PPCFixupKinds.h
@@ -12,6 +12,8 @@
 
 #include "llvm/MC/MCFixup.h"
 
+#undef PPC
+
 namespace llvm {
 namespace PPC {
 enum Fixups {
diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.h b/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.h
index 4a420929d07..38a7420d972 100644
--- a/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.h
+++ b/lib/Target/PowerPC/MCTargetDesc/PPCMCTargetDesc.h
@@ -47,6 +47,10 @@ MCObjectWriter *createPPCELFObjectWriter(raw_ostream &OS,
                                          uint8_t OSABI);
 } // End llvm namespace
 
+// Generated files will use "namespace PPC". To avoid symbol clash,
+// undefine PPC here. PPC may be predefined on some hosts.
+#undef PPC
+
 // Defines symbolic names for PowerPC registers.  This defines a mapping from
 // register name to register number.
 //
diff --git a/lib/Target/PowerPC/MCTargetDesc/PPCPredicates.h b/lib/Target/PowerPC/MCTargetDesc/PPCPredicates.h
index 972e13852ed..b0680fbb8c6 100644
--- a/lib/Target/PowerPC/MCTargetDesc/PPCPredicates.h
+++ b/lib/Target/PowerPC/MCTargetDesc/PPCPredicates.h
@@ -17,6 +17,10 @@
 // GCC #defines PPC on Linux but we use it as our namespace name
 #undef PPC
 
+// Generated files will use "namespace PPC". To avoid symbol clash,
+// undefine PPC here. PPC may be predefined on some hosts.
+#undef PPC
+
 namespace llvm {
 namespace PPC {
   /// Predicate - These are "(BI << 5) | BO"  for various predicates.