diff --git a/builtin/checkout.c b/builtin/checkout.c
index 92017ba6696..9641423dc2f 100644
--- a/builtin/checkout.c
+++ b/builtin/checkout.c
@@ -1687,7 +1687,7 @@ static int checkout_main(int argc, const char **argv, const char *prefix,
 
 	if (opts->conflict_style) {
 		opts->merge = 1; /* implied */
-		git_xmerge_config("merge.conflictstyle", opts->conflict_style, NULL);
+		git_xmerge_config("merge.conflictstyle", opts->conflict_style, NULL, NULL);
 	}
 	if (opts->force) {
 		opts->discard_changes = 1;
diff --git a/builtin/clone.c b/builtin/clone.c
index 1e1cf104194..e654757c45d 100644
--- a/builtin/clone.c
+++ b/builtin/clone.c
@@ -791,14 +791,14 @@ static int git_clone_config(const char *k, const char *v,
 }
 
 static int write_one_config(const char *key, const char *value,
-			    struct key_value_info *kvi UNUSED, void *data)
+			    struct key_value_info *kvi, void *data)
 {
 	/*
 	 * give git_clone_config a chance to write config values back to the
 	 * environment, since git_config_set_multivar_gently only deals with
 	 * config-file writes
 	 */
-	int apply_failed = git_clone_config(key, value, data);
+	int apply_failed = git_clone_config(key, value, kvi, data);
 	if (apply_failed)
 		return apply_failed;
 
diff --git a/builtin/grep.c b/builtin/grep.c
index 177befc3ed4..6e795f9f3a2 100644
--- a/builtin/grep.c
+++ b/builtin/grep.c
@@ -290,7 +290,7 @@ static int wait_all(void)
 static int grep_cmd_config(const char *var, const char *value,
 			   struct key_value_info *kvi, void *cb)
 {
-	int st = grep_config(var, value, cb);
+	int st = grep_config(var, value, kvi, cb);
 
 	if (git_color_config(var, value, cb) < 0)
 		st = -1;
diff --git a/compat/mingw.c b/compat/mingw.c
index 94c5a1daa40..c8181469a2f 100644
--- a/compat/mingw.c
+++ b/compat/mingw.c
@@ -242,7 +242,8 @@ static int core_restrict_inherited_handles = -1;
 static enum hide_dotfiles_type hide_dotfiles = HIDE_DOTFILES_DOTGITONLY;
 static char *unset_environment_variables;
 
-int mingw_core_config(const char *var, const char *value, void *cb)
+int mingw_core_config(const char *var, const char *value,
+		      struct key_value_info *kvi UNUSED, void *cb)
 {
 	if (!strcmp(var, "core.hidedotfiles")) {
 		if (value && !strcasecmp(value, "dotgitonly"))
diff --git a/compat/mingw.h b/compat/mingw.h
index 209cf7cebad..4f2b489b883 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -11,7 +11,9 @@ typedef _sigset_t sigset_t;
 #undef _POSIX_THREAD_SAFE_FUNCTIONS
 #endif
 
-int mingw_core_config(const char *var, const char *value, void *cb);
+struct key_value_info;
+int mingw_core_config(const char *var, const char *value,
+		      struct key_value_info *, void *cb);
 #define platform_core_config mingw_core_config
 
 /*
diff --git a/diff.h b/diff.h
index 6a3efa63753..2ceb0fd2d66 100644
--- a/diff.h
+++ b/diff.h
@@ -532,6 +532,7 @@ void free_diffstat_info(struct diffstat_t *diffstat);
 int parse_long_opt(const char *opt, const char **argv,
 		   const char **optarg);
 
+struct key_value_info;
 int git_diff_basic_config(const char *var, const char *value,
 			  struct key_value_info *kvi, void *cb);
 int git_diff_heuristic_config(const char *var, const char *value, void *cb);
diff --git a/fsck.h b/fsck.h
index a06f202576c..914e67a067d 100644
--- a/fsck.h
+++ b/fsck.h
@@ -233,6 +233,7 @@ void fsck_put_object_name(struct fsck_options *options,
 const char *fsck_describe_object(struct fsck_options *options,
 				 const struct object_id *oid);
 
+struct key_value_info;
 /*
  * git_config() callback for use by fsck-y tools that want to support
  * fsck.<msg> fsck.skipList etc.
diff --git a/git-compat-util.h b/git-compat-util.h
index 4a200a9fb41..6812b592c15 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -440,8 +440,10 @@ typedef uintmax_t timestamp_t;
 #endif
 
 #ifndef platform_core_config
+struct key_value_info;
 static inline int noop_core_config(const char *var UNUSED,
 				   const char *value UNUSED,
+				   struct key_value_info *kvi UNUSED,
 				   void *cb UNUSED)
 {
 	return 0;
diff --git a/grep.c b/grep.c
index 1516b0689d0..2d3b9bf5d92 100644
--- a/grep.c
+++ b/grep.c
@@ -55,7 +55,7 @@ define_list_config_array_extra(color_grep_slots, {"match"});
  * the grep_defaults template.
  */
 int grep_config(const char *var, const char *value,
-		struct key_value_info *kvi UNUSED, void *cb)
+		struct key_value_info *kvi, void *cb)
 {
 	struct grep_opt *opt = cb;
 	const char *slot;
@@ -90,9 +90,9 @@ int grep_config(const char *var, const char *value,
 	if (!strcmp(var, "color.grep"))
 		opt->color = git_config_colorbool(var, value);
 	if (!strcmp(var, "color.grep.match")) {
-		if (grep_config("color.grep.matchcontext", value, cb) < 0)
+		if (grep_config("color.grep.matchcontext", value, kvi, cb) < 0)
 			return -1;
-		if (grep_config("color.grep.matchselected", value, cb) < 0)
+		if (grep_config("color.grep.matchselected", value, kvi, cb) < 0)
 			return -1;
 	} else if (skip_prefix(var, "color.grep.", &slot)) {
 		int i = LOOKUP_CONFIG(color_grep_slots, slot);
diff --git a/grep.h b/grep.h
index c59592e3bdb..6d2fb0ada54 100644
--- a/grep.h
+++ b/grep.h
@@ -202,7 +202,9 @@ struct grep_opt {
 	.output = std_output, \
 }
 
-int grep_config(const char *var, const char *value, void *);
+struct key_value_info;
+int grep_config(const char *var, const char *value, struct key_value_info *kvi,
+		void *);
 void grep_init(struct grep_opt *, struct repository *repo);
 
 void append_grep_pat(struct grep_opt *opt, const char *pat, size_t patlen, const char *origin, int no, enum grep_pat_token t);
diff --git a/http.c b/http.c
index d5d82c5230f..3d4292eba6a 100644
--- a/http.c
+++ b/http.c
@@ -361,7 +361,8 @@ static void process_curl_messages(void)
 	}
 }
 
-static int http_options(const char *var, const char *value, void *cb)
+static int http_options(const char *var, const char *value,
+			struct key_value_info *kvi, void *cb)
 {
 	if (!strcmp("http.version", var)) {
 		return git_config_string(&curl_http_version, var, value);
@@ -532,7 +533,7 @@ static int http_options(const char *var, const char *value, void *cb)
 	}
 
 	/* Fall back on the default ones */
-	return git_default_config(var, value, cb);
+	return git_default_config(var, value, kvi, cb);
 }
 
 static int curl_empty_auth_enabled(void)
diff --git a/ident.h b/ident.h
index f55db41ff99..4e3bd347c52 100644
--- a/ident.h
+++ b/ident.h
@@ -62,7 +62,8 @@ const char *fmt_name(enum want_ident);
 int committer_ident_sufficiently_given(void);
 int author_ident_sufficiently_given(void);
 
+struct key_value_info;
 int git_ident_config(const char *, const char *,
-		     struct key_value_info *UNUSED, void *);
+		     struct key_value_info *, void *);
 
 #endif
diff --git a/submodule-config.c b/submodule-config.c
index fb12d8040e8..0b794b6f32e 100644
--- a/submodule-config.c
+++ b/submodule-config.c
@@ -675,7 +675,7 @@ out:
 }
 
 static int gitmodules_cb(const char *var, const char *value,
-			 struct key_value_info *kvi UNUSED, void *data)
+			 struct key_value_info *kvi, void *data)
 {
 	struct repository *repo = data;
 	struct parse_config_parameter parameter;
@@ -685,7 +685,7 @@ static int gitmodules_cb(const char *var, const char *value,
 	parameter.gitmodules_oid = null_oid();
 	parameter.overwrite = 1;
 
-	return parse_config(var, value, &parameter);
+	return parse_config(var, value, kvi, &parameter);
 }
 
 void repo_read_gitmodules(struct repository *repo, int skip_if_read)
diff --git a/trace2/tr2_cfg.c b/trace2/tr2_cfg.c
index 6871258d468..8ed139c69f4 100644
--- a/trace2/tr2_cfg.c
+++ b/trace2/tr2_cfg.c
@@ -146,5 +146,5 @@ void tr2_cfg_set_fl(const char *file, int line, const char *key,
 	struct tr2_cfg_data data = { file, line };
 
 	if (tr2_cfg_load_patterns() > 0)
-		tr2_cfg_cb(key, value, &data);
+		tr2_cfg_cb(key, value, NULL, &data);
 }
diff --git a/urlmatch.c b/urlmatch.c
index 47683974d8c..c94500b61b3 100644
--- a/urlmatch.c
+++ b/urlmatch.c
@@ -552,7 +552,7 @@ static int cmp_matches(const struct urlmatch_item *a,
 }
 
 int urlmatch_config_entry(const char *var, const char *value,
-			  struct key_value_info *kvi UNUSED, void *cb)
+			  struct key_value_info *kvi, void *cb)
 {
 	struct string_list_item *item;
 	struct urlmatch_config *collect = cb;
@@ -566,7 +566,7 @@ int urlmatch_config_entry(const char *var, const char *value,
 
 	if (!skip_prefix(var, collect->section, &key) || *(key++) != '.') {
 		if (collect->cascade_fn)
-			return collect->cascade_fn(var, value, cb);
+			return collect->cascade_fn(var, value, kvi, cb);
 		return 0; /* not interested */
 	}
 	dot = strrchr(key, '.');
@@ -610,7 +610,7 @@ int urlmatch_config_entry(const char *var, const char *value,
 	strbuf_addstr(&synthkey, collect->section);
 	strbuf_addch(&synthkey, '.');
 	strbuf_addstr(&synthkey, key);
-	retval = collect->collect_fn(synthkey.buf, value, collect->cb);
+	retval = collect->collect_fn(synthkey.buf, value, kvi, collect->cb);
 
 	strbuf_release(&synthkey);
 	return retval;
diff --git a/xdiff-interface.h b/xdiff-interface.h
index c1676b11702..749cdf77579 100644
--- a/xdiff-interface.h
+++ b/xdiff-interface.h
@@ -50,6 +50,8 @@ int buffer_is_binary(const char *ptr, unsigned long size);
 
 void xdiff_set_find_func(xdemitconf_t *xecfg, const char *line, int cflags);
 void xdiff_clear_find_func(xdemitconf_t *xecfg);
+
+struct key_value_info;
 int git_xmerge_config(const char *var, const char *value,
 		      struct key_value_info *kvi, void *cb);
 extern int git_xmerge_style;
