diff --git a/add-patch.c b/add-patch.c
index 4c803a5f4d..e59830291a 100644
--- a/add-patch.c
+++ b/add-patch.c
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "add-interactive.h"
 #include "alloc.h"
+#include "environment.h"
 #include "gettext.h"
 #include "strbuf.h"
 #include "run-command.h"
diff --git a/builtin/branch.c b/builtin/branch.c
index a67a8334d5..56dbee97d2 100644
--- a/builtin/branch.c
+++ b/builtin/branch.c
@@ -8,6 +8,7 @@
 #include "cache.h"
 #include "config.h"
 #include "color.h"
+#include "environment.h"
 #include "refs.h"
 #include "commit.h"
 #include "builtin.h"
diff --git a/builtin/commit.c b/builtin/commit.c
index 25575435ad..42bf20f589 100644
--- a/builtin/commit.c
+++ b/builtin/commit.c
@@ -12,6 +12,7 @@
 #include "cache-tree.h"
 #include "color.h"
 #include "dir.h"
+#include "environment.h"
 #include "builtin.h"
 #include "diff.h"
 #include "diffcore.h"
diff --git a/builtin/merge.c b/builtin/merge.c
index a90ae5d2dd..2c9da4b23d 100644
--- a/builtin/merge.c
+++ b/builtin/merge.c
@@ -10,6 +10,7 @@
 #include "cache.h"
 #include "alloc.h"
 #include "config.h"
+#include "environment.h"
 #include "gettext.h"
 #include "hex.h"
 #include "parse-options.h"
diff --git a/builtin/tag.c b/builtin/tag.c
index c2ea89c475..0611b3bd60 100644
--- a/builtin/tag.c
+++ b/builtin/tag.c
@@ -9,6 +9,7 @@
 #include "cache.h"
 #include "config.h"
 #include "builtin.h"
+#include "environment.h"
 #include "gettext.h"
 #include "hex.h"
 #include "refs.h"
diff --git a/cache.h b/cache.h
index 5a736a2b7e..e122de6f93 100644
--- a/cache.h
+++ b/cache.h
@@ -959,13 +959,6 @@ extern int sparse_expect_files_outside_of_patterns;
  */
 int use_optional_locks(void);
 
-/*
- * The character that begins a commented line in user-editable file
- * that is subject to stripspace.
- */
-extern char comment_line_char;
-extern int auto_comment_line_char;
-
 enum log_refs_config {
 	LOG_REFS_UNSET = -1,
 	LOG_REFS_NONE = 0,
diff --git a/commit.c b/commit.c
index 3fdfb32511..f88fc5e1a2 100644
--- a/commit.c
+++ b/commit.c
@@ -2,6 +2,7 @@
 #include "tag.h"
 #include "commit.h"
 #include "commit-graph.h"
+#include "environment.h"
 #include "gettext.h"
 #include "hex.h"
 #include "repository.h"
diff --git a/environment.h b/environment.h
index d438b5c8f3..a26931556a 100644
--- a/environment.h
+++ b/environment.h
@@ -3,6 +3,13 @@
 
 #include "strvec.h"
 
+/*
+ * The character that begins a commented line in user-editable file
+ * that is subject to stripspace.
+ */
+extern char comment_line_char;
+extern int auto_comment_line_char;
+
 /*
  * Wrapper of getenv() that returns a strdup value. This value is kept
  * in argv to be freed later.
diff --git a/fmt-merge-msg.c b/fmt-merge-msg.c
index c870cb95b9..bc4e61c5b1 100644
--- a/fmt-merge-msg.c
+++ b/fmt-merge-msg.c
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "alloc.h"
 #include "config.h"
+#include "environment.h"
 #include "refs.h"
 #include "object-store.h"
 #include "diff.h"
diff --git a/sequencer.c b/sequencer.c
index 0df5172630..7fa776b061 100644
--- a/sequencer.c
+++ b/sequencer.c
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "alloc.h"
 #include "config.h"
+#include "environment.h"
 #include "gettext.h"
 #include "hex.h"
 #include "lockfile.h"
diff --git a/strbuf.c b/strbuf.c
index 15209777d5..b9cd593b14 100644
--- a/strbuf.c
+++ b/strbuf.c
@@ -1,5 +1,6 @@
 #include "cache.h"
 #include "alloc.h"
+#include "environment.h"
 #include "gettext.h"
 #include "hex.h"
 #include "refs.h"
diff --git a/trailer.c b/trailer.c
index 9eb1b76119..6a5091a3c4 100644
--- a/trailer.c
+++ b/trailer.c
@@ -1,6 +1,7 @@
 #include "cache.h"
 #include "alloc.h"
 #include "config.h"
+#include "environment.h"
 #include "gettext.h"
 #include "string-list.h"
 #include "run-command.h"
diff --git a/wt-status.c b/wt-status.c
index d15f2b0e7e..106e46480a 100644
--- a/wt-status.c
+++ b/wt-status.c
@@ -4,6 +4,7 @@
 #include "dir.h"
 #include "commit.h"
 #include "diff.h"
+#include "environment.h"
 #include "gettext.h"
 #include "hex.h"
 #include "revision.h"