2 files changed, 19 insertions, 1 deletions
diff --git a/internal/accept/accept.go b/internal/accept/accept.go
index 5ed6e66..c23905a 100644
--- a/internal/accept/accept.go
+++ b/internal/accept/accept.go
@@ -103,6 +103,11 @@ func (h Header) Negotiate(mediaTypes ...string) Option[string] {
 		return None[string]()
 	}
 
+	// if nothing was offered, we default to our own preferred option
+	if len(h.options) == 0 {
+		return Some(offers[0].OriginalValue)
+	}
+
 	// NOTE: ParseHeader() sorts options by descending weight, so the first match wins.
 	for _, opt := range h.options {
 	MEDIATYPE:
@@ -128,5 +133,5 @@ func (h Header) Negotiate(mediaTypes ...string) Option[string] {
 		}
 	}
 
-	return Some(offers[0].OriginalValue)
+	return None[string]()
 }
diff --git a/internal/accept/accept_test.go b/internal/accept/accept_test.go
index 90b6934..edfef42 100644
--- a/internal/accept/accept_test.go
+++ b/internal/accept/accept_test.go
@@ -12,6 +12,7 @@ import (
 )
 
 func TestAcceptWithHeader(t *testing.T) {
+	// asking for a wide range of formats, including wildcard matches
 	h := accept.ParseHeader([]string{"text/*;q=0.3, text/plain;format=flowed, text/plain;format=fixed;q=0.4, */*;q=0.5"})
 
 	assert.Equal(t, h.Negotiate(
@@ -38,6 +39,18 @@ func TestAcceptWithHeader(t *testing.T) {
 		"text/markdown", // matches with q=0.3
 		"text/plain",    // matches with q=0.3 (but first wins)
 	), Some("text/markdown"))
+
+	// asking for specific formats only
+	h = accept.ParseHeader([]string{"image/png, image/jpeg"})
+
+	assert.Equal(t, h.Negotiate(
+		"text/plain",
+		"image/png",
+	), Some("image/png"))
+
+	assert.Equal(t, h.Negotiate(
+		"text/plain",
+	), None[string]())
 }
 
 func TestAcceptWithoutHeader(t *testing.T) {