diff --git a/internal/app/api/html_test.go b/internal/app/api/html_test.go
index 8ee252b9..9df49a96 100644
--- a/internal/app/api/html_test.go
+++ b/internal/app/api/html_test.go
@@ -17,5 +17,8 @@ func TestHTML(t *testing.T) {
 	rec := httptest.NewRecorder()
 	e := echo.New()
 	c := e.NewContext(req, rec)
-	assert.NoError(t, convertHTML(c))
+	if assert.NoError(t, convertHTML(c)) {
+		assert.Equal(t, http.StatusOK, rec.Code)
+		assert.Equal(t, "application/pdf", rec.Header().Get(echo.HeaderContentType))
+	}
 }
diff --git a/internal/app/api/markdown_test.go b/internal/app/api/markdown_test.go
index a399d58a..3a979c99 100644
--- a/internal/app/api/markdown_test.go
+++ b/internal/app/api/markdown_test.go
@@ -17,5 +17,8 @@ func TestMarkdown(t *testing.T) {
 	rec := httptest.NewRecorder()
 	e := echo.New()
 	c := e.NewContext(req, rec)
-	assert.NoError(t, convertMarkdown(c))
+	if assert.NoError(t, convertMarkdown(c)) {
+		assert.Equal(t, http.StatusOK, rec.Code)
+		assert.Equal(t, "application/pdf", rec.Header().Get(echo.HeaderContentType))
+	}
 }
diff --git a/internal/app/api/merge_test.go b/internal/app/api/merge_test.go
index 4d147887..14e49c84 100644
--- a/internal/app/api/merge_test.go
+++ b/internal/app/api/merge_test.go
@@ -17,5 +17,8 @@ func TestMerge(t *testing.T) {
 	rec := httptest.NewRecorder()
 	e := echo.New()
 	c := e.NewContext(req, rec)
-	assert.NoError(t, merge(c))
+	if assert.NoError(t, merge(c)) {
+		assert.Equal(t, http.StatusOK, rec.Code)
+		assert.Equal(t, "application/pdf", rec.Header().Get(echo.HeaderContentType))
+	}
 }
diff --git a/internal/app/api/office_test.go b/internal/app/api/office_test.go
index a46c4c8f..2c85bf55 100644
--- a/internal/app/api/office_test.go
+++ b/internal/app/api/office_test.go
@@ -17,5 +17,8 @@ func TestOffice(t *testing.T) {
 	rec := httptest.NewRecorder()
 	e := echo.New()
 	c := e.NewContext(req, rec)
-	assert.NoError(t, convertOffice(c))
+	if assert.NoError(t, convertOffice(c)) {
+		assert.Equal(t, http.StatusOK, rec.Code)
+		assert.Equal(t, "application/pdf", rec.Header().Get(echo.HeaderContentType))
+	}
 }