diff --git a/compiler-rt/lib/scudo/standalone/combined.h b/compiler-rt/lib/scudo/standalone/combined.h
--- a/compiler-rt/lib/scudo/standalone/combined.h
+++ b/compiler-rt/lib/scudo/standalone/combined.h
@@ -727,10 +727,12 @@
   void iterateOverChunks(uptr Base, uptr Size, iterate_callback Callback,
                          void *Arg) {
     initThreadMaybe();
-    const uptr From = Base;
-    const uptr To = Base + Size;
     bool MayHaveTaggedPrimary = allocatorSupportsMemoryTagging<Params>() &&
                                 systemSupportsMemoryTagging();
+    if (MayHaveTaggedPrimary)
+      Base = untagPointer(Base);
+    const uptr From = Base;
+    const uptr To = Base + Size;
     auto Lambda = [this, From, To, MayHaveTaggedPrimary, Callback,
                    Arg](uptr Block) {
       if (Block < From || Block >= To)
diff --git a/compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp b/compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp
--- a/compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp
+++ b/compiler-rt/lib/scudo/standalone/tests/wrappers_c_test.cpp
@@ -6,6 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
+#include "memtag.h"
 #include "scudo/interface.h"
 #include "tests/scudo_unit_test.h"
 
@@ -277,7 +278,7 @@
 static size_t Count;
 
 static void callback(uintptr_t Base, size_t Size, void *Arg) {
-  if (Base == BoundaryP)
+  if (scudo::untagPointer(Base) == scudo::untagPointer(BoundaryP))
     Count++;
 }