diff --git a/CMakeLists.txt b/CMakeLists.txt
index 317ad34f9..3cf271c63 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -293,12 +293,12 @@ ENDIF()
 
 # Specify sha1 implementation
 IF (WIN32 AND NOT MINGW AND NOT SHA1_TYPE STREQUAL "builtin")
-	ADD_DEFINITIONS(-DWIN32_SHA1)
+	ADD_DEFINITIONS(-DGIT_SHA1_WIN32)
 	FILE(GLOB SRC_SHA1 src/hash/hash_win32.c)
 ELSEIF (${CMAKE_SYSTEM_NAME} MATCHES "Darwin")
-	ADD_DEFINITIONS(-DGIT_COMMON_CRYPTO)
+	ADD_DEFINITIONS(-DGIT_SHA1_COMMON_CRYPTO)
 ELSEIF (OPENSSL_FOUND AND NOT SHA1_TYPE STREQUAL "builtin")
-	ADD_DEFINITIONS(-DOPENSSL_SHA1)
+	ADD_DEFINITIONS(-DGIT_SHA1_OPENSSL)
 	IF (CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
 		LIST(APPEND LIBGIT2_PC_LIBS "-lssl")
 	ELSE()
diff --git a/src/hash.h b/src/hash.h
index 0bc02a8a9..76788b18d 100644
--- a/src/hash.h
+++ b/src/hash.h
@@ -16,11 +16,11 @@ int git_hash_global_init(void);
 int git_hash_ctx_init(git_hash_ctx *ctx);
 void git_hash_ctx_cleanup(git_hash_ctx *ctx);
 
-#if defined(GIT_COMMON_CRYPTO)
+#if defined(GIT_SHA1_COMMON_CRYPTO)
 # include "hash/hash_common_crypto.h"
-#elif defined(OPENSSL_SHA1)
+#elif defined(GIT_SHA1_OPENSSL)
 # include "hash/hash_openssl.h"
-#elif defined(WIN32_SHA1)
+#elif defined(GIT_SHA1_WIN32)
 # include "hash/hash_win32.h"
 #else
 # include "hash/hash_generic.h"