diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_allocator_combined.h b/compiler-rt/lib/sanitizer_common/sanitizer_allocator_combined.h
index b92cfa5bf4c4b..b76d36dcf5a4e 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_allocator_combined.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_allocator_combined.h
@@ -134,7 +134,7 @@ class CombinedAllocator {
 
   // This function does the same as GetBlockBegin, but is much faster.
   // Must be called with the allocator locked.
-  void *GetBlockBeginFastLocked(void *p) {
+  void *GetBlockBeginFastLocked(const void *p) {
     if (primary_.PointerIsMine(p))
       return primary_.GetBlockBegin(p);
     return secondary_.GetBlockBeginFastLocked(p);
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_allocator_secondary.h b/compiler-rt/lib/sanitizer_common/sanitizer_allocator_secondary.h
index 48afb2a298341..1576455556044 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_allocator_secondary.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_allocator_secondary.h
@@ -215,7 +215,7 @@ class LargeMmapAllocator {
 
   // This function does the same as GetBlockBegin, but is much faster.
   // Must be called with the allocator locked.
-  void *GetBlockBeginFastLocked(void *ptr) {
+  void *GetBlockBeginFastLocked(const void *ptr) {
     mutex_.CheckLocked();
     uptr p = reinterpret_cast<uptr>(ptr);
     uptr n = n_chunks_;