diff --git a/libsodium.vcxproj b/libsodium.vcxproj
index d9661cea..6ca8ee20 100644
--- a/libsodium.vcxproj
+++ b/libsodium.vcxproj
@@ -328,7 +328,7 @@
     <ClInclude Include="src\libsodium\include\sodium\crypto_generichash.h" />
     <ClInclude Include="src\libsodium\include\sodium\crypto_generichash_blake2b.h" />
     <ClInclude Include="src\libsodium\include\sodium\crypto_hash.h" />
-    <ClInclude Include="src\libsodium\include\sodium\crypto_hashblocks_sha512.h" />
+    <ClInclude Include="src\libsodium\include\sodium\_crypto_hashblocks_sha512.h" />
     <ClInclude Include="src\libsodium\include\sodium\crypto_hash_sha256.h" />
     <ClInclude Include="src\libsodium\include\sodium\crypto_hash_sha512.h" />
     <ClInclude Include="src\libsodium\include\sodium\crypto_int32.h" />
diff --git a/libsodium.vcxproj.filters b/libsodium.vcxproj.filters
index 4921729a..96890124 100644
--- a/libsodium.vcxproj.filters
+++ b/libsodium.vcxproj.filters
@@ -60,7 +60,7 @@
     <ClInclude Include="src\libsodium\include\sodium\crypto_hash_sha512.h">
       <Filter>Header Files</Filter>
     </ClInclude>
-    <ClInclude Include="src\libsodium\include\sodium\crypto_hashblocks_sha512.h">
+    <ClInclude Include="src\libsodium\include\sodium\_crypto_hashblocks_sha512.h">
       <Filter>Header Files</Filter>
     </ClInclude>
     <ClInclude Include="src\libsodium\include\sodium\crypto_int32.h">
diff --git a/src/libsodium/crypto_auth/hmacsha512256/ref/hmac_hmacsha512256.c b/src/libsodium/crypto_auth/hmacsha512256/ref/hmac_hmacsha512256.c
index be871ced..d3ebfd96 100644
--- a/src/libsodium/crypto_auth/hmacsha512256/ref/hmac_hmacsha512256.c
+++ b/src/libsodium/crypto_auth/hmacsha512256/ref/hmac_hmacsha512256.c
@@ -5,7 +5,7 @@
  * */
 
 #include "api.h"
-#include "crypto_hashblocks_sha512.h"
+#include "_crypto_hashblocks_sha512.h"
 
 #define blocks crypto_hashblocks_sha512
 
diff --git a/src/libsodium/crypto_hash/sha512/ref/hash_sha512.c b/src/libsodium/crypto_hash/sha512/ref/hash_sha512.c
index 7cc8b85d..fc66045e 100644
--- a/src/libsodium/crypto_hash/sha512/ref/hash_sha512.c
+++ b/src/libsodium/crypto_hash/sha512/ref/hash_sha512.c
@@ -5,7 +5,7 @@ Public domain.
 */
 
 #include "api.h"
-#include "crypto_hashblocks_sha512.h"
+#include "_crypto_hashblocks_sha512.h"
 
 #define blocks crypto_hashblocks_sha512
 
diff --git a/src/libsodium/crypto_hashblocks/sha512/ref/api.h b/src/libsodium/crypto_hashblocks/sha512/ref/api.h
index 1662652d..5086bd1c 100644
--- a/src/libsodium/crypto_hashblocks/sha512/ref/api.h
+++ b/src/libsodium/crypto_hashblocks/sha512/ref/api.h
@@ -1,5 +1,5 @@
 
-#include "crypto_hashblocks_sha512.h"
+#include "_crypto_hashblocks_sha512.h"
 
 #define crypto_hashblocks crypto_hashblocks_sha512
 #define crypto_hashblocks_STATEBYTES crypto_hashblocks_sha512_STATEBYTES
diff --git a/src/libsodium/include/Makefile.am b/src/libsodium/include/Makefile.am
index 3cd4e359..c945ba8b 100644
--- a/src/libsodium/include/Makefile.am
+++ b/src/libsodium/include/Makefile.am
@@ -16,7 +16,6 @@ SODIUM_EXPORT = \
 	sodium/crypto_hash.h \
 	sodium/crypto_hash_sha256.h \
 	sodium/crypto_hash_sha512.h \
-	sodium/crypto_hashblocks_sha512.h \
 	sodium/crypto_onetimeauth.h \
 	sodium/crypto_onetimeauth_poly1305.h \
 	sodium/crypto_onetimeauth_poly1305_53.h \
@@ -53,6 +52,7 @@ SODIUM_EXPORT = \
 	sodium/utils.h
 
 EXTRA_SRC = $(SODIUM_EXPORT) \
+	sodium/_crypto_hashblocks_sha512.h \
 	sodium/version.h.in
 
 nobase_include_HEADERS = $(SODIUM_EXPORT)
diff --git a/src/libsodium/include/sodium/crypto_hashblocks_sha512.h b/src/libsodium/include/sodium/_crypto_hashblocks_sha512.h
similarity index 76%
rename from src/libsodium/include/sodium/crypto_hashblocks_sha512.h
rename to src/libsodium/include/sodium/_crypto_hashblocks_sha512.h
index bfa74407..3b51a3c5 100644
--- a/src/libsodium/include/sodium/crypto_hashblocks_sha512.h
+++ b/src/libsodium/include/sodium/_crypto_hashblocks_sha512.h
@@ -1,5 +1,5 @@
-#ifndef crypto_hashblocks_sha512_H
-#define crypto_hashblocks_sha512_H
+#ifndef _crypto_hashblocks_sha512_H
+#define _crypto_hashblocks_sha512_H
 
 #include <stddef.h>
 #include "export.h"
@@ -13,7 +13,8 @@
 # endif
 extern "C" {
 #endif
-    
+
+/* This function is only used internally */
 int crypto_hashblocks_sha512(unsigned char *,const unsigned char *,unsigned long long);
 
 #ifdef __cplusplus