diff --git a/compiler-rt/lib/lsan/lsan_allocator.h b/compiler-rt/lib/lsan/lsan_allocator.h
--- a/compiler-rt/lib/lsan/lsan_allocator.h
+++ b/compiler-rt/lib/lsan/lsan_allocator.h
@@ -69,19 +69,26 @@
 # if SANITIZER_FUCHSIA || defined(__powerpc64__)
 const uptr kAllocatorSpace = ~(uptr)0;
 const uptr kAllocatorSize  =  0x40000000000ULL;  // 4T.
+typedef DefaultSizeClassMap SizeClassMap;
+#  elif SANITIZER_RISCV64
+const uptr kAllocatorSpace = ~(uptr)0;
+const uptr kAllocatorSize  =  0x2000000000ULL;  // 128G.
+typedef VeryDenseSizeClassMap SizeClassMap;
 #  elif SANITIZER_APPLE
 const uptr kAllocatorSpace = 0x600000000000ULL;
 const uptr kAllocatorSize  = 0x40000000000ULL;  // 4T.
+typedef DefaultSizeClassMap SizeClassMap;
 #  else
 const uptr kAllocatorSpace = 0x500000000000ULL;
 const uptr kAllocatorSize = 0x40000000000ULL;  // 4T.
+typedef DefaultSizeClassMap SizeClassMap;
 #  endif
 template <typename AddressSpaceViewTy>
 struct AP64 {  // Allocator64 parameters. Deliberately using a short name.
   static const uptr kSpaceBeg = kAllocatorSpace;
   static const uptr kSpaceSize = kAllocatorSize;
   static const uptr kMetadataSize = sizeof(ChunkMetadata);
-  typedef DefaultSizeClassMap SizeClassMap;
+  typedef __lsan::SizeClassMap SizeClassMap;
   typedef NoOpMapUnmapCallback MapUnmapCallback;
   static const uptr kFlags = 0;
   using AddressSpaceView = AddressSpaceViewTy;