diff --git a/Documentation/git-interpret-trailers.txt b/Documentation/git-interpret-trailers.txt
index 9111c47a1b..152479ebba 100644
--- a/Documentation/git-interpret-trailers.txt
+++ b/Documentation/git-interpret-trailers.txt
@@ -56,8 +56,9 @@ least one Git-generated or user-configured trailer and consists of at
 least 25% trailers.
 The group must be preceded by one or more empty (or whitespace-only) lines.
 The group must either be at the end of the message or be the last
-non-whitespace lines before a line that starts with '---'. Such three
-minus signs start the patch part of the message.
+non-whitespace lines before a line that starts with '---' (followed by a
+space or the end of the line). Such three minus signs start the patch
+part of the message.
 
 When reading trailers, there can be whitespaces after the
 token, the separator and the value. There can also be whitespaces
diff --git a/t/t7513-interpret-trailers.sh b/t/t7513-interpret-trailers.sh
index 164719d1c9..e13b40b43f 100755
--- a/t/t7513-interpret-trailers.sh
+++ b/t/t7513-interpret-trailers.sh
@@ -1417,4 +1417,26 @@ test_expect_success 'unfold' '
 	test_cmp expected actual
 '
 
+test_expect_success 'handling of --- lines in input' '
+	echo "real-trailer: just right" >expected &&
+
+	git interpret-trailers --parse >actual <<-\EOF &&
+	subject
+
+	body
+
+	not-a-trailer: too soon
+	------ this is just a line in the commit message with a bunch of
+	------ dashes; it does not have any syntactic meaning.
+
+	real-trailer: just right
+	---
+	below the dashed line may be a patch, etc.
+
+	not-a-trailer: too late
+	EOF
+
+	test_cmp expected actual
+'
+
 test_done
diff --git a/trailer.c b/trailer.c
index e769c5b72c..8392c6c030 100644
--- a/trailer.c
+++ b/trailer.c
@@ -793,7 +793,9 @@ static size_t find_patch_start(const char *str)
 	const char *s;
 
 	for (s = str; *s; s = next_line(s)) {
-		if (starts_with(s, "---"))
+		const char *v;
+
+		if (skip_prefix(s, "---", &v) && isspace(*v))
 			return s - str;
 	}