diff --git a/src/mips/assembler-mips.h b/src/mips/assembler-mips.h
index ea34e7a440..c6be19158c 100644
--- a/src/mips/assembler-mips.h
+++ b/src/mips/assembler-mips.h
@@ -475,8 +475,7 @@ class MemOperand : public Operand {
   friend class Assembler;
 };
 
-
-class Assembler : public AssemblerBase {
+class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
  public:
   // Create an assembler. Instructions and relocation information are emitted
   // into a buffer, with the instructions starting from the beginning and the
diff --git a/src/mips/macro-assembler-mips.h b/src/mips/macro-assembler-mips.h
index 52bd959be1..cb4dcc32e0 100644
--- a/src/mips/macro-assembler-mips.h
+++ b/src/mips/macro-assembler-mips.h
@@ -131,7 +131,7 @@ inline MemOperand CFunctionArgumentOperand(int index) {
   return MemOperand(sp, offset);
 }
 
-class TurboAssembler : public TurboAssemblerBase {
+class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
  public:
   TurboAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int buffer_size,
diff --git a/src/mips64/assembler-mips64.h b/src/mips64/assembler-mips64.h
index f94db35974..164e2ebf02 100644
--- a/src/mips64/assembler-mips64.h
+++ b/src/mips64/assembler-mips64.h
@@ -482,8 +482,7 @@ class MemOperand : public Operand {
   friend class Assembler;
 };
 
-
-class Assembler : public AssemblerBase {
+class V8_EXPORT_PRIVATE Assembler : public AssemblerBase {
  public:
   // Create an assembler. Instructions and relocation information are emitted
   // into a buffer, with the instructions starting from the beginning and the
diff --git a/src/mips64/macro-assembler-mips64.h b/src/mips64/macro-assembler-mips64.h
index 695bde26b6..c3ea63fa8e 100644
--- a/src/mips64/macro-assembler-mips64.h
+++ b/src/mips64/macro-assembler-mips64.h
@@ -148,7 +148,7 @@ inline MemOperand CFunctionArgumentOperand(int index) {
   return MemOperand(sp, offset);
 }
 
-class TurboAssembler : public TurboAssemblerBase {
+class V8_EXPORT_PRIVATE TurboAssembler : public TurboAssemblerBase {
  public:
   TurboAssembler(Isolate* isolate, const AssemblerOptions& options,
                  void* buffer, int buffer_size,