diff --git a/common/utils.cc b/common/utils.cc
index f7d4585..dd2afea 100644
--- a/common/utils.cc
+++ b/common/utils.cc
@@ -58,7 +58,6 @@
 #include "update_engine/common/subprocess.h"
 #include "update_engine/payload_consumer/file_descriptor.h"
 #include "update_engine/payload_consumer/file_writer.h"
-#include "update_engine/payload_consumer/payload_constants.h"
 
 using base::Time;
 using base::TimeDelta;
@@ -1011,19 +1010,6 @@
   return false;
 }
 
-bool IsZlibCompatible(const string& fingerprint) {
-  if (fingerprint.size() != sizeof(kCompatibleZlibFingerprint[0]) - 1) {
-    LOG(ERROR) << "Invalid fingerprint: " << fingerprint;
-    return false;
-  }
-  for (auto& f : kCompatibleZlibFingerprint) {
-    if (base::CompareCaseInsensitiveASCII(fingerprint, f) == 0) {
-      return true;
-    }
-  }
-  return false;
-}
-
 bool ReadExtents(const string& path, const vector<Extent>& extents,
                  brillo::Blob* out_data, ssize_t out_data_size,
                  size_t block_size) {
diff --git a/common/utils.h b/common/utils.h
index e950b15..d009fbb 100644
--- a/common/utils.h
+++ b/common/utils.h
@@ -305,9 +305,6 @@
 bool GetMinorVersion(const brillo::KeyValueStore& store,
                      uint32_t* minor_version);
 
-// Returns whether zlib |fingerprint| is compatible with zlib we are using.
-bool IsZlibCompatible(const std::string& fingerprint);
-
 // This function reads the specified data in |extents| into |out_data|. The
 // extents are read from the file at |path|. |out_data_size| is the size of
 // |out_data|. Returns false if the number of bytes to read given in
diff --git a/payload_consumer/delta_performer_unittest.cc b/payload_consumer/delta_performer_unittest.cc
index 09bbb7c..52d19e0 100644
--- a/payload_consumer/delta_performer_unittest.cc
+++ b/payload_consumer/delta_performer_unittest.cc
@@ -68,13 +68,6 @@
     "fjoTeLYZpt+WN65Vu7jJ0cQN8e1y+2yka5112wpRf/LLtPgiAjEZnsoYpLUd7CoV"
     "pLRtClp97kN2+tXGNBQqkA==";
 
-#ifdef __ANDROID__
-const char kZlibFingerprintPath[] =
-    "/data/nativetest/update_engine_unittests/zlib_fingerprint";
-#else
-const char kZlibFingerprintPath[] = "/etc/zlib_fingerprint";
-#endif  // __ANDROID__
-
 // Different options that determine what we should fill into the
 // install_plan.metadata_signature to simulate the contents received in the
 // Omaha response.
@@ -901,14 +894,4 @@
   EXPECT_EQ(DeltaPerformer::kSupportedMajorPayloadVersion, major_version);
 }
 
-// Test that we recognize our own zlib compressor implementation as supported.
-// All other equivalent implementations should be added to
-// kCompatibleZlibFingerprint.
-TEST_F(DeltaPerformerTest, ZlibFingerprintMatch) {
-  string fingerprint;
-  EXPECT_TRUE(base::ReadFileToString(base::FilePath(kZlibFingerprintPath),
-                                     &fingerprint));
-  EXPECT_TRUE(utils::IsZlibCompatible(fingerprint));
-}
-
 }  // namespace chromeos_update_engine
diff --git a/payload_consumer/payload_constants.cc b/payload_consumer/payload_constants.cc
index 6078a74..3d78e0a 100644
--- a/payload_consumer/payload_constants.cc
+++ b/payload_consumer/payload_constants.cc
@@ -33,15 +33,6 @@
 const char kDeltaMagic[4] = {'C', 'r', 'A', 'U'};
 const char kBspatchPath[] = "bspatch";
 
-// The zlib in Android and Chrome OS are currently compatible with each other,
-// so they are sharing the same array, but if in the future they are no longer
-// compatible with each other, we coule make the same change on the other one to
-// make them compatible again or use ifdef here.
-const char kCompatibleZlibFingerprint[][65] = {
-    "ea973605ccbbdb24f59f449c5f65861a1a9bc7a4353377aaaa06cb3e0f1cfbd7",
-    "3747fa404cceb00a5ec3606fc779510aaa784d5864ab1d5c28b9e267c40aad5c",
-};
-
 const char* InstallOperationTypeName(InstallOperation_Type op_type) {
   switch (op_type) {
     case InstallOperation::BSDIFF:
diff --git a/payload_consumer/payload_constants.h b/payload_consumer/payload_constants.h
index 2dbc5fa..76d740f 100644
--- a/payload_consumer/payload_constants.h
+++ b/payload_consumer/payload_constants.h
@@ -56,15 +56,6 @@
 extern const char kBspatchPath[];
 extern const char kDeltaMagic[4];
 
-// The list of compatible SHA256 hashes of zlib source code.
-// This is used to check if the source image have a compatible zlib (produce
-// same compressed result given the same input).
-// When a new fingerprint is found, please examine the changes in zlib source
-// carefully and determine if it's still compatible with previous version, if
-// yes then add the new fingerprint to this array, otherwise remove all previous
-// fingerprints in the array first, and only include the new fingerprint.
-extern const char kCompatibleZlibFingerprint[2][65];
-
 // A block number denoting a hole on a sparse file. Used on Extents to refer to
 // section of blocks not present on disk on a sparse file.
 const uint64_t kSparseHole = std::numeric_limits<uint64_t>::max();
diff --git a/payload_generator/generate_delta_main.cc b/payload_generator/generate_delta_main.cc
index 99af679..9014369 100644
--- a/payload_generator/generate_delta_main.cc
+++ b/payload_generator/generate_delta_main.cc
@@ -310,9 +310,6 @@
   DEFINE_string(properties_file, "",
                 "If passed, dumps the payload properties of the payload passed "
                 "in --in_file and exits.");
-  DEFINE_string(zlib_fingerprint, "",
-                "The fingerprint of zlib in the source image in hash string "
-                "format, used to check imgdiff compatibility.");
 
   DEFINE_string(old_channel, "",
                 "The channel for the old image. 'dev-channel', 'npo-channel', "
@@ -542,14 +539,6 @@
     LOG(INFO) << "Using provided minor_version=" << FLAGS_minor_version;
   }
 
-  if (!FLAGS_zlib_fingerprint.empty()) {
-    if (utils::IsZlibCompatible(FLAGS_zlib_fingerprint)) {
-      payload_config.version.imgdiff_allowed = true;
-    } else {
-      LOG(INFO) << "IMGDIFF operation disabled due to fingerprint mismatch.";
-    }
-  }
-
   if (payload_config.is_delta) {
     LOG(INFO) << "Generating delta update";
   } else {
diff --git a/scripts/brillo_update_payload b/scripts/brillo_update_payload
index a3eec4b..75b089d 100755
--- a/scripts/brillo_update_payload
+++ b/scripts/brillo_update_payload
@@ -200,9 +200,6 @@
 # Path to the postinstall config file in target image if exists.
 POSTINSTALL_CONFIG_FILE=""
 
-# The fingerprint of zlib in the source image.
-ZLIB_FINGERPRINT=""
-
 # read_option_int <file.txt> <option_key> [default_value]
 #
 # Reads the unsigned integer value associated with |option_key| in a key=value
@@ -310,11 +307,6 @@
   # updater supports a newer major version.
   FORCE_MAJOR_VERSION="1"
 
-  if [[ "${partitions_array}" == "SRC_PARTITIONS" ]]; then
-    # Copy from zlib_fingerprint in source image to stdout.
-    ZLIB_FINGERPRINT=$(e2cp "${root}":/etc/zlib_fingerprint -)
-  fi
-
   # When generating legacy Chrome OS images, we need to use "boot" and "system"
   # for the partition names to be compatible with updating Brillo devices with
   # Chrome OS images.
@@ -388,10 +380,6 @@
 Disabling deltas for this source version."
       exit ${EX_UNSUPPORTED_DELTA}
     fi
-
-    if [[ "${FORCE_MINOR_VERSION}" -ge 4 ]]; then
-      ZLIB_FINGERPRINT=$(unzip -p "${image}" "META/zlib_fingerprint.txt")
-    fi
   else
     # Target image
     local postinstall_config=$(create_tempfile "postinstall_config.XXXXXX")
@@ -487,9 +475,6 @@
     if [[ -n "${FORCE_MINOR_VERSION}" ]]; then
       GENERATOR_ARGS+=( --minor_version="${FORCE_MINOR_VERSION}" )
     fi
-    if [[ -n "${ZLIB_FINGERPRINT}" ]]; then
-      GENERATOR_ARGS+=( --zlib_fingerprint="${ZLIB_FINGERPRINT}" )
-    fi
   fi
 
   if [[ -n "${FORCE_MAJOR_VERSION}" ]]; then