diff --git a/upb/message/BUILD b/upb/message/BUILD
index 102bf87003..d5dc0d0a4b 100644
--- a/upb/message/BUILD
+++ b/upb/message/BUILD
@@ -99,10 +99,8 @@ cc_library(
         ":internal",
         ":message",
         "//upb:base",
-        "//upb:mem",
         "//upb:mini_table",
         "//upb:port",
-        "//upb:wire",
         "//upb/mini_table:internal",
     ],
 )
diff --git a/upb/message/compare.c b/upb/message/compare.c
index 20d97945c7..acd06b2529 100644
--- a/upb/message/compare.c
+++ b/upb/message/compare.c
@@ -7,10 +7,9 @@
 
 #include "upb/message/compare.h"
 
-#include <string.h>
+#include <stddef.h>
 
 #include "upb/base/descriptor_constants.h"
-#include "upb/mem/arena.h"
 #include "upb/message/accessors.h"
 #include "upb/message/array.h"
 #include "upb/message/internal/accessors.h"
@@ -22,7 +21,6 @@
 #include "upb/mini_table/field.h"
 #include "upb/mini_table/internal/field.h"
 #include "upb/mini_table/message.h"
-#include "upb/wire/encode.h"
 
 // Must be last.
 #include "upb/port/def.inc"
@@ -237,28 +235,3 @@ bool upb_Message_IsEqual(const upb_Message* msg1, const upb_Message* msg2,
   return UPB_PRIVATE(_upb_Message_UnknownFieldsAreEqual)(
              uf1, usize1, uf2, usize2, 100) == kUpb_UnknownCompareResult_Equal;
 }
-
-bool upb_Message_IsExactlyEqual(const upb_Message* msg1,
-                                const upb_Message* msg2,
-                                const upb_MiniTable* m) {
-  if (msg1 == msg2) return true;
-
-  int opts = kUpb_EncodeOption_SkipUnknown | kUpb_EncodeOption_Deterministic;
-  upb_Arena* a = upb_Arena_New();
-
-  // Compare deterministically serialized payloads with no unknown fields.
-  size_t size1, size2;
-  char *data1, *data2;
-  upb_EncodeStatus status1 = upb_Encode(msg1, m, opts, a, &data1, &size1);
-  upb_EncodeStatus status2 = upb_Encode(msg2, m, opts, a, &data2, &size2);
-
-  if (status1 != kUpb_EncodeStatus_Ok || status2 != kUpb_EncodeStatus_Ok) {
-    // TODO: How should we fail here? (In Ruby we throw an exception.)
-    upb_Arena_Free(a);
-    return false;
-  }
-
-  const bool ret = (size1 == size2) && (memcmp(data1, data2, size1) == 0);
-  upb_Arena_Free(a);
-  return ret;
-}
diff --git a/upb/message/compare.h b/upb/message/compare.h
index 892147108c..00822fbe44 100644
--- a/upb/message/compare.h
+++ b/upb/message/compare.h
@@ -32,11 +32,6 @@ UPB_API bool upb_Message_IsEqual(const upb_Message* msg1,
                                  const upb_Message* msg2,
                                  const upb_MiniTable* m);
 
-// Compares two messages by serializing them and calling memcmp().
-UPB_API bool upb_Message_IsExactlyEqual(const upb_Message* msg1,
-                                        const upb_Message* msg2,
-                                        const upb_MiniTable* m);
-
 // If |ctype| is a message then |m| must point to its minitable.
 UPB_API_INLINE bool upb_MessageValue_IsEqual(upb_MessageValue val1,
                                              upb_MessageValue val2,