diff --git a/notmuch-show.c b/notmuch-show.c
index ab1cd144..36265043 100644
--- a/notmuch-show.c
+++ b/notmuch-show.c
@@ -759,7 +759,16 @@ format_part_sprinter (const void *ctx, sprinter_t *sp, mime_node_t *node,
 	    sp->string_len (sp, (char *) part_content->data, part_content->len);
 	    g_object_unref (stream_memory);
 	} else {
-	    format_omitted_part_meta_sprinter (sp, meta, GMIME_PART (node->part));
+	    /* if we have a child part despite being a standard
+	     * (non-multipart) MIME part, that means there is
+	     * something to unwrap, which we will present in
+	     * content: */
+	    if (node->nchildren) {
+		sp->map_key (sp, "content");
+		sp->begin_list (sp);
+		nclose = 1;
+	    } else
+		format_omitted_part_meta_sprinter (sp, meta, GMIME_PART (node->part));
 	}
     } else if (GMIME_IS_MULTIPART (node->part)) {
 	sp->map_key (sp, "content");
diff --git a/test/T355-smime.sh b/test/T355-smime.sh
index 4de0fbef..03aada20 100755
--- a/test/T355-smime.sh
+++ b/test/T355-smime.sh
@@ -177,12 +177,10 @@ On Tue, 26 Nov 2019 20:11:29 -0400, Alice Lovelace <alice@smime.example> wrote:
 test_expect_equal "$expected" "$output"
 
 test_begin_subtest "show PKCS#7 SignedData outputs valid JSON"
-test_subtest_known_broken
 output=$(notmuch show --format=json id:smime-onepart-signed@protected-headers.example)
 test_valid_json "$output"
 
 test_begin_subtest "Verify signature on PKCS#7 SignedData message"
-test_subtest_known_broken
 output=$(notmuch show --format=json id:smime-onepart-signed@protected-headers.example)
 
 test_json_nodes <<<"$output" \
@@ -192,7 +190,9 @@ test_json_nodes <<<"$output" \
                 'status:[0][0][0]["crypto"]["signed"]["status"][0]["status"]="good"'
 
 test_begin_subtest "Verify signature on PKCS#7 SignedData message signer User ID"
-test_subtest_known_broken
+if [ $NOTMUCH_GMIME_X509_CERT_VALIDITY -ne 1 ]; then
+    test_subtest_known_broken
+fi
 test_json_nodes <<<"$output" \
                 'userid:[0][0][0]["crypto"]["signed"]["status"][0]["userid"]="CN=Alice Lovelace"'
 
diff --git a/test/T356-protected-headers.sh b/test/T356-protected-headers.sh
index 5fd27434..5beffaf0 100755
--- a/test/T356-protected-headers.sh
+++ b/test/T356-protected-headers.sh
@@ -157,7 +157,6 @@ test_expect_equal "$output" id:protected-with-legacy-display@crypto.notmuchmail.
 
 for variant in multipart-signed onepart-signed; do
     test_begin_subtest "verify signed PKCS#7 subject ($variant)"
-    [ "$variant" = multipart-signed ] || test_subtest_known_broken
     output=$(notmuch show --verify --format=json "id:smime-${variant}@protected-headers.example")
     test_json_nodes <<<"$output" \
                     'signed_subject:[0][0][0]["crypto"]["signed"]["headers"]=["Subject"]' \
@@ -165,7 +164,7 @@ for variant in multipart-signed onepart-signed; do
                     'sig_fpr:[0][0][0]["crypto"]["signed"]["status"][0]["fingerprint"]="702BA4B157F1E2B7D16B0C6A5FFC8A7DE2057DEB"' \
                     'not_encrypted:[0][0][0]["crypto"]!"decrypted"'
     test_begin_subtest "verify signed PKCS#7 subject ($variant) signer User ID"
-    if [ $NOTMUCH_GMIME_X509_CERT_VALIDITY -ne 1 ] || [ "$variant" != multipart-signed ]; then
+    if [ $NOTMUCH_GMIME_X509_CERT_VALIDITY -ne 1 ]; then
         test_subtest_known_broken
     fi
     test_json_nodes <<<"$output" \