diff --git a/builtin/config.c b/builtin/config.c
index fc8d8820cb..20e89fe4e0 100644
--- a/builtin/config.c
+++ b/builtin/config.c
@@ -119,7 +119,8 @@ static int format_config(struct strbuf *buf, const char *key_, const char *value
 		must_print_delim = 1;
 	}
 	if (types == TYPE_INT)
-		sprintf(value, "%d", git_config_int(key_, value_ ? value_ : ""));
+		sprintf(value, "%"PRId64,
+			git_config_int64(key_, value_ ? value_ : ""));
 	else if (types == TYPE_BOOL)
 		vptr = git_config_bool(key_, value_) ? "true" : "false";
 	else if (types == TYPE_BOOL_OR_INT) {
@@ -268,8 +269,8 @@ static char *normalize_value(const char *key, const char *value)
 	else {
 		normalized = xmalloc(64);
 		if (types == TYPE_INT) {
-			int v = git_config_int(key, value);
-			sprintf(normalized, "%d", v);
+			int64_t v = git_config_int64(key, value);
+			sprintf(normalized, "%"PRId64, v);
 		}
 		else if (types == TYPE_BOOL)
 			sprintf(normalized, "%s",
diff --git a/cache.h b/cache.h
index 9ef778a5a9..a47b9c0303 100644
--- a/cache.h
+++ b/cache.h
@@ -1115,6 +1115,7 @@ extern int git_config_with_options(config_fn_t fn, void *,
 extern int git_config_early(config_fn_t fn, void *, const char *repo_config);
 extern int git_parse_ulong(const char *, unsigned long *);
 extern int git_config_int(const char *, const char *);
+extern int64_t git_config_int64(const char *, const char *);
 extern unsigned long git_config_ulong(const char *, const char *);
 extern int git_config_bool_or_int(const char *, const char *, int *);
 extern int git_config_bool(const char *, const char *);
diff --git a/config.c b/config.c
index 9f9bf0cc9a..6588cf579f 100644
--- a/config.c
+++ b/config.c
@@ -468,7 +468,7 @@ static int parse_unit_factor(const char *end, uintmax_t *val)
 	return 0;
 }
 
-static int git_parse_long(const char *value, long *ret)
+static int git_parse_signed(const char *value, intmax_t *ret, intmax_t max)
 {
 	if (value && *value) {
 		char *end;
@@ -480,21 +480,25 @@ static int git_parse_long(const char *value, long *ret)
 		val = strtoimax(value, &end, 0);
 		if (errno == ERANGE)
 			return 0;
-		if (!parse_unit_factor(end, &factor))
+		if (!parse_unit_factor(end, &factor)) {
+			errno = EINVAL;
 			return 0;
+		}
 		uval = abs(val);
 		uval *= factor;
-		if ((uval > maximum_signed_value_of_type(long)) ||
-		    (abs(val) > uval))
+		if (uval > max || abs(val) > uval) {
+			errno = ERANGE;
 			return 0;
+		}
 		val *= factor;
 		*ret = val;
 		return 1;
 	}
+	errno = EINVAL;
 	return 0;
 }
 
-int git_parse_ulong(const char *value, unsigned long *ret)
+int git_parse_unsigned(const char *value, uintmax_t *ret, uintmax_t max)
 {
 	if (value && *value) {
 		char *end;
@@ -506,29 +510,75 @@ int git_parse_ulong(const char *value, unsigned long *ret)
 		if (errno == ERANGE)
 			return 0;
 		oldval = val;
-		if (!parse_unit_factor(end, &val))
+		if (!parse_unit_factor(end, &val)) {
+			errno = EINVAL;
 			return 0;
-		if ((val > maximum_unsigned_value_of_type(long)) ||
-		    (oldval > val))
+		}
+		if (val > max || oldval > val) {
+			errno = ERANGE;
 			return 0;
+		}
 		*ret = val;
 		return 1;
 	}
+	errno = EINVAL;
 	return 0;
 }
 
-static void die_bad_config(const char *name)
+static int git_parse_int(const char *value, int *ret)
 {
+	intmax_t tmp;
+	if (!git_parse_signed(value, &tmp, maximum_signed_value_of_type(int)))
+		return 0;
+	*ret = tmp;
+	return 1;
+}
+
+static int git_parse_int64(const char *value, int64_t *ret)
+{
+	intmax_t tmp;
+	if (!git_parse_signed(value, &tmp, maximum_signed_value_of_type(int64_t)))
+		return 0;
+	*ret = tmp;
+	return 1;
+}
+
+int git_parse_ulong(const char *value, unsigned long *ret)
+{
+	uintmax_t tmp;
+	if (!git_parse_unsigned(value, &tmp, maximum_unsigned_value_of_type(long)))
+		return 0;
+	*ret = tmp;
+	return 1;
+}
+
+static void die_bad_number(const char *name, const char *value)
+{
+	const char *reason = errno == ERANGE ?
+			     "out of range" :
+			     "invalid unit";
+	if (!value)
+		value = "";
+
 	if (cf && cf->name)
-		die("bad config value for '%s' in %s", name, cf->name);
-	die("bad config value for '%s'", name);
+		die("bad numeric config value '%s' for '%s' in %s: %s",
+		    value, name, cf->name, reason);
+	die("bad numeric config value '%s' for '%s': %s", value, name, reason);
 }
 
 int git_config_int(const char *name, const char *value)
 {
-	long ret = 0;
-	if (!git_parse_long(value, &ret))
-		die_bad_config(name);
+	int ret;
+	if (!git_parse_int(value, &ret))
+		die_bad_number(name, value);
+	return ret;
+}
+
+int64_t git_config_int64(const char *name, const char *value)
+{
+	int64_t ret;
+	if (!git_parse_int64(value, &ret))
+		die_bad_number(name, value);
 	return ret;
 }
 
@@ -536,7 +586,7 @@ unsigned long git_config_ulong(const char *name, const char *value)
 {
 	unsigned long ret;
 	if (!git_parse_ulong(value, &ret))
-		die_bad_config(name);
+		die_bad_number(name, value);
 	return ret;
 }
 
@@ -559,10 +609,10 @@ static int git_config_maybe_bool_text(const char *name, const char *value)
 
 int git_config_maybe_bool(const char *name, const char *value)
 {
-	long v = git_config_maybe_bool_text(name, value);
+	int v = git_config_maybe_bool_text(name, value);
 	if (0 <= v)
 		return v;
-	if (git_parse_long(value, &v))
+	if (git_parse_int(value, &v))
 		return !!v;
 	return -1;
 }
diff --git a/t/t1300-repo-config.sh b/t/t1300-repo-config.sh
index c23f4781e1..967359344d 100755
--- a/t/t1300-repo-config.sh
+++ b/t/t1300-repo-config.sh
@@ -652,16 +652,23 @@ test_expect_success numbers '
 	test_cmp expect actual
 '
 
+test_expect_success '--int is at least 64 bits' '
+	git config giga.watts 121g &&
+	echo 129922760704 >expect &&
+	git config --int --get giga.watts >actual &&
+	test_cmp expect actual
+'
+
 test_expect_success 'invalid unit' '
 	git config aninvalid.unit "1auto" &&
 	echo 1auto >expect &&
 	git config aninvalid.unit >actual &&
 	test_cmp expect actual &&
-	cat > expect <<-\EOF
-	fatal: bad config value for '\''aninvalid.unit'\'' in .git/config
+	cat >expect <<-\EOF
+	fatal: bad numeric config value '\''1auto'\'' for '\''aninvalid.unit'\'' in .git/config: invalid unit
 	EOF
 	test_must_fail git config --int --get aninvalid.unit 2>actual &&
-	test_cmp actual expect
+	test_i18ncmp expect actual
 '
 
 cat > expect << EOF
diff --git a/t/t4055-diff-context.sh b/t/t4055-diff-context.sh
index 97172b46b2..cd0454356a 100755
--- a/t/t4055-diff-context.sh
+++ b/t/t4055-diff-context.sh
@@ -73,7 +73,7 @@ test_expect_success 'plumbing not affected' '
 test_expect_success 'non-integer config parsing' '
 	git config diff.context no &&
 	test_must_fail git diff 2>output &&
-	test_i18ngrep "bad config value" output
+	test_i18ngrep "bad numeric config value" output
 '
 
 test_expect_success 'negative integer config parsing' '