diff --git a/cdatapack/cdatapack_get.c b/cdatapack/cdatapack_get.c
--- a/cdatapack/cdatapack_get.c
+++ b/cdatapack/cdatapack_get.c
@@ -6,12 +6,12 @@
 
 #include <inttypes.h>
 #include <memory.h>
-#include <sha1dc/sha1.h>
 #include <stdio.h>
 #include <stdlib.h>
 
+#include "cdatapack.h"
+#include "clib/sha1.h"
 #include "convert.h"
-#include "cdatapack.h"
 
 #define DATAIDX_EXT  ".dataidx"
 #define DATAPACK_EXT ".datapack"
@@ -81,10 +81,10 @@
   for (int ix = 0; ix < chain.links_count; ix ++) {
     delta_chain_link_t *link = &chain.delta_chain_links[ix];
 
-    SHA1_CTX ctx;
-    SHA1DCInit(&ctx);
-    SHA1DCUpdate(&ctx, link->delta, link->delta_sz);
-    SHA1DCFinal(sha, &ctx);
+    fbhg_sha1_ctx_t ctx;
+    fbhg_sha1_init(&ctx);
+    fbhg_sha1_update(&ctx, link->delta, link->delta_sz);
+    fbhg_sha1_final(sha, &ctx);
 
     if (last_filename_sz != link->filename_sz ||
         memcmp(last_filename, link->filename, last_filename_sz) != 0) {
diff --git a/cfastmanifest/checksum.c b/cfastmanifest/checksum.c
--- a/cfastmanifest/checksum.c
+++ b/cfastmanifest/checksum.c
@@ -5,14 +5,13 @@
 //
 // no-check-code
 
-#include <sha1dc/sha1.h>
-
+#include "clib/sha1.h"
 #include "node.h"
 #include "tree.h"
 
 static void update_checksum(node_t *node) {
-  SHA1_CTX ctx;
-  SHA1DCInit(&ctx);
+  fbhg_sha1_ctx_t ctx;
+  fbhg_sha1_init(&ctx);
 
   // find all the children and make sure their checksums are up-to-date.
   for (child_num_t ix = 0; ix < node->num_children; ix++) {
@@ -21,12 +20,12 @@
       update_checksum(child);
     }
 
-    SHA1DCUpdate(&ctx, (const unsigned char*) child->name, child->name_sz);
-    SHA1DCUpdate(&ctx, child->checksum, child->checksum_sz);
-    SHA1DCUpdate(&ctx, &child->flags, 1);
+    fbhg_sha1_update(&ctx, child->name, child->name_sz);
+    fbhg_sha1_update(&ctx, child->checksum, child->checksum_sz);
+    fbhg_sha1_update(&ctx, &child->flags, 1);
   }
 
-  SHA1DCFinal(node->checksum, &ctx);
+  fbhg_sha1_final(node->checksum, &ctx);
   node->checksum_sz = SHA1_BYTES;
   node->checksum_valid = true;
 }
diff --git a/clib/sha1.h b/clib/sha1.h
new file mode 100644
--- /dev/null
+++ b/clib/sha1.h
@@ -0,0 +1,38 @@
+// Copyright (c) 2017-present, Facebook, Inc.
+// All Rights Reserved.
+//
+// This software may be used and distributed according to the terms of the
+// GNU General Public License version 2 or any later version.
+
+// sha1.h - wrapper functions around the underlying SHA-1 implementation.
+//
+// no-check-code
+#pragma once
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+#include <stdlib.h>
+#include <sha1dc/sha1.h>
+
+typedef SHA1_CTX fbhg_sha1_ctx_t;
+
+static inline int fbhg_sha1_init(fbhg_sha1_ctx_t* ctx) {
+  SHA1DCInit(ctx);
+  return 0;
+}
+
+static inline int
+fbhg_sha1_update(fbhg_sha1_ctx_t* ctx, const void* data, unsigned long length) {
+  SHA1DCUpdate(ctx, (const unsigned char*)data, length);
+  return 0;
+}
+
+static inline int fbhg_sha1_final(unsigned char* md, fbhg_sha1_ctx_t* ctx) {
+  return SHA1DCFinal(md, ctx);
+}
+
+#ifdef __cplusplus
+} /* extern C */
+#endif
diff --git a/ctreemanifest/manifest.cpp b/ctreemanifest/manifest.cpp
--- a/ctreemanifest/manifest.cpp
+++ b/ctreemanifest/manifest.cpp
@@ -7,9 +7,8 @@
 //
 // no-check-code
 
-#include <sha1dc/sha1.h>
-
 #include "manifest.h"
+#include "clib/sha1.h"
 
 Manifest::Manifest(ConstantStringRef &rawobj, const char *node) :
     _rawobj(rawobj),
@@ -232,19 +231,19 @@
   std::string content;
   this->serialize(content);
 
-  SHA1_CTX ctx;
-  SHA1DCInit(&ctx);
+  fbhg_sha1_ctx_t ctx;
+  fbhg_sha1_init(&ctx);
 
   if (memcmp(p1, p2, BIN_NODE_SIZE) == -1) {
-    SHA1DCUpdate(&ctx, (const unsigned char *) p1, BIN_NODE_SIZE);
-    SHA1DCUpdate(&ctx, (const unsigned char *) p2, BIN_NODE_SIZE);
+    fbhg_sha1_update(&ctx, p1, BIN_NODE_SIZE);
+    fbhg_sha1_update(&ctx, p2, BIN_NODE_SIZE);
   } else {
-    SHA1DCUpdate(&ctx, (const unsigned char *)p2, BIN_NODE_SIZE);
-    SHA1DCUpdate(&ctx, (const unsigned char *)p1, BIN_NODE_SIZE);
+    fbhg_sha1_update(&ctx, p2, BIN_NODE_SIZE);
+    fbhg_sha1_update(&ctx, p1, BIN_NODE_SIZE);
   }
-  SHA1DCUpdate(&ctx, (const unsigned char *)content.c_str(), content.size());
+  fbhg_sha1_update(&ctx, content.c_str(), content.size());
 
-  SHA1DCFinal((unsigned char*)result, &ctx);
+  fbhg_sha1_final((unsigned char*)result, &ctx);
 }
 
 ManifestPtr::ManifestPtr() :
diff --git a/setup.py b/setup.py
--- a/setup.py
+++ b/setup.py
@@ -245,6 +245,7 @@
                     'ctreemanifest/treemanifest.cpp',
                 ],
                 include_dirs=[
+                    '.',
                     'ctreemanifest',
                     'cdatapack',
                     'clib',
@@ -280,6 +281,7 @@
                          'cfastmanifest/tree_path.c',
                 ],
                 include_dirs=[
+                    '.',
                     'cfastmanifest',
                     'clib',
                     'third-party',
diff --git a/tests/test-check-code-hg.t b/tests/test-check-code-hg.t
--- a/tests/test-check-code-hg.t
+++ b/tests/test-check-code-hg.t
@@ -57,6 +57,7 @@
   Skipping clib/buffer.c it has no-che?k-code (glob)
   Skipping clib/buffer.h it has no-che?k-code (glob)
   Skipping clib/null_test.c it has no-che?k-code (glob)
+  Skipping clib/sha1.h it has no-che?k-code (glob)
   Skipping cstore/datapackstore.cpp it has no-che?k-code (glob)
   Skipping cstore/datapackstore.h it has no-che?k-code (glob)
   Skipping cstore/key.h it has no-che?k-code (glob)