diff --git a/llvm/lib/Target/Hexagon/HexagonISelDAGToDAG.h b/llvm/lib/Target/Hexagon/HexagonISelDAGToDAG.h
index 7b5e7634ebf62a..d60de4cfc2eeb8 100644
--- a/llvm/lib/Target/Hexagon/HexagonISelDAGToDAG.h
+++ b/llvm/lib/Target/Hexagon/HexagonISelDAGToDAG.h
@@ -25,7 +25,6 @@ namespace llvm {
 class MachineFunction;
 class HexagonInstrInfo;
 class HexagonRegisterInfo;
-class HexagonTargetLowering;
 
 class HexagonDAGToDAGISel : public SelectionDAGISel {
   const HexagonSubtarget *HST;
diff --git a/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCExpr.h b/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCExpr.h
index 59b1326adf0ccc..e88f46a04dae41 100644
--- a/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCExpr.h
+++ b/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCExpr.h
@@ -12,7 +12,6 @@
 #include "llvm/MC/MCExpr.h"
 
 namespace llvm {
-class MCInst;
 class HexagonMCExpr : public MCTargetExpr {
 public:
   static HexagonMCExpr *create(MCExpr const *Expr, MCContext &Ctx);
diff --git a/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCTargetDesc.h b/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCTargetDesc.h
index a089abc3bd0c49..5bf7c9a1a908d6 100644
--- a/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCTargetDesc.h
+++ b/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCTargetDesc.h
@@ -47,7 +47,6 @@
 
 namespace llvm {
 
-struct InstrItinerary;
 struct InstrStage;
 class FeatureBitset;
 class MCAsmBackend;
@@ -61,8 +60,6 @@ class MCTargetOptions;
 class Target;
 class Triple;
 class StringRef;
-class raw_ostream;
-class raw_pwrite_stream;
 
 extern cl::opt<bool> HexagonDisableCompound;
 extern cl::opt<bool> HexagonDisableDuplex;