diff --git a/t/helper/test-cache-tree.c b/t/helper/test-cache-tree.c
index 5514afdfe7..9159a17301 100644
--- a/t/helper/test-cache-tree.c
+++ b/t/helper/test-cache-tree.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_VARIABLE
 #include "test-tool.h"
 #include "cache.h"
 #include "tree.h"
diff --git a/t/helper/test-dump-cache-tree.c b/t/helper/test-dump-cache-tree.c
index 4bf8bc3df6..454f17b1a0 100644
--- a/t/helper/test-dump-cache-tree.c
+++ b/t/helper/test-dump-cache-tree.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_VARIABLE
 #include "test-tool.h"
 #include "cache.h"
 #include "tree.h"
diff --git a/t/helper/test-dump-split-index.c b/t/helper/test-dump-split-index.c
index a209880eb3..0ea97b8407 100644
--- a/t/helper/test-dump-split-index.c
+++ b/t/helper/test-dump-split-index.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_VARIABLE
 #include "test-tool.h"
 #include "cache.h"
 #include "split-index.h"
diff --git a/t/helper/test-dump-untracked-cache.c b/t/helper/test-dump-untracked-cache.c
index ffe34736e5..6d53683f13 100644
--- a/t/helper/test-dump-untracked-cache.c
+++ b/t/helper/test-dump-untracked-cache.c
@@ -1,4 +1,4 @@
-#define USE_THE_INDEX_COMPATIBILITY_MACROS
+#define USE_THE_INDEX_VARIABLE
 #include "test-tool.h"
 #include "cache.h"
 #include "dir.h"
diff --git a/t/helper/test-fast-rebase.c b/t/helper/test-fast-rebase.c
index 9def2ba688..efc82dd80c 100644
--- a/t/helper/test-fast-rebase.c
+++ b/t/helper/test-fast-rebase.c
@@ -10,7 +10,7 @@
  * refactoring is the better route).
  */
 
-#define USE_THE_INDEX_COMPATIBILITY_MACROS
+#define USE_THE_INDEX_VARIABLE
 #include "test-tool.h"
 
 #include "cache-tree.h"
diff --git a/t/helper/test-lazy-init-name-hash.c b/t/helper/test-lazy-init-name-hash.c
index 7e8723a190..ab86c14c8b 100644
--- a/t/helper/test-lazy-init-name-hash.c
+++ b/t/helper/test-lazy-init-name-hash.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_VARIABLE
 #include "test-tool.h"
 #include "cache.h"
 #include "parse-options.h"
diff --git a/t/helper/test-read-cache.c b/t/helper/test-read-cache.c
index a089be9104..23e9e27109 100644
--- a/t/helper/test-read-cache.c
+++ b/t/helper/test-read-cache.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_VARIABLE
 #include "test-tool.h"
 #include "cache.h"
 #include "config.h"
diff --git a/t/helper/test-scrap-cache-tree.c b/t/helper/test-scrap-cache-tree.c
index 9206dee1fd..a26107ed70 100644
--- a/t/helper/test-scrap-cache-tree.c
+++ b/t/helper/test-scrap-cache-tree.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_VARIABLE
 #include "test-tool.h"
 #include "cache.h"
 #include "lockfile.h"
diff --git a/t/helper/test-tool.h b/t/helper/test-tool.h
index da7cd6351a..2e20a16eb8 100644
--- a/t/helper/test-tool.h
+++ b/t/helper/test-tool.h
@@ -1,7 +1,6 @@
 #ifndef TEST_TOOL_H
 #define TEST_TOOL_H
 
-#define USE_THE_INDEX_COMPATIBILITY_MACROS
 #include "git-compat-util.h"
 
 int cmd__advise_if_enabled(int argc, const char **argv);
diff --git a/t/helper/test-write-cache.c b/t/helper/test-write-cache.c
index 66287d6d47..7d45cd61e8 100644
--- a/t/helper/test-write-cache.c
+++ b/t/helper/test-write-cache.c
@@ -1,3 +1,4 @@
+#define USE_THE_INDEX_VARIABLE
 #include "test-tool.h"
 #include "cache.h"
 #include "lockfile.h"