diff --git a/openssl-sys/src/pkcs7.rs b/openssl-sys/src/pkcs7.rs
index 454a04dfcfb03055bb88a243a12879ee229a1991..5aa55ff8b5a75458e81031a380be70ac44846591 100644
--- a/openssl-sys/src/pkcs7.rs
+++ b/openssl-sys/src/pkcs7.rs
@@ -29,6 +29,10 @@ pub const PKCS7_REUSE_DIGEST: c_int = 0x8000;
 pub const PKCS7_NO_DUAL_CONTENT: c_int = 0x10000;
 
 extern "C" {
+    pub fn d2i_PKCS7(a: *mut *mut PKCS7, pp: *mut *const c_uchar, length: c_long) -> *mut PKCS7;
+
+    pub fn i2d_PKCS7(a: *mut PKCS7, buf: *mut *mut u8) -> c_int;
+
     pub fn PKCS7_encrypt(
         certs: *mut stack_st_X509,
         b: *mut BIO,
diff --git a/openssl/src/pkcs7.rs b/openssl/src/pkcs7.rs
index a4d93cf958984f9c6634b7ff82e37c2796e4b83a..7820739c0cb03f0a99a36dad71cc76e690deb1f1 100644
--- a/openssl/src/pkcs7.rs
+++ b/openssl/src/pkcs7.rs
@@ -61,6 +61,17 @@ impl Pkcs7 {
         ffi::PEM_read_bio_PKCS7
     }
 
+    from_der! {
+        /// Deserializes a DER-encoded PKCS#7 signature
+        ///
+        /// This corresponds to [`d2i_PKCS7`].
+        ///
+        /// [`d2i_PKCS7`]: https://www.openssl.org/docs/man1.1.0/man3/d2i_PKCS7.html
+        from_der,
+        Pkcs7,
+        ffi::d2i_PKCS7
+    }
+
     /// Parses a message in S/MIME format.
     ///
     /// Returns the loaded signature, along with the cleartext message (if
@@ -181,6 +192,16 @@ impl Pkcs7Ref {
         ffi::PEM_write_bio_PKCS7
     }
 
+    to_der! {
+        /// Serializes the data into a DER-encoded PKCS#7 structure.
+        ///
+        /// This corresponds to [`i2d_PKCS7`].
+        ///
+        /// [`i2d_PKCS7`]: https://www.openssl.org/docs/man1.1.0/man3/i2d_PKCS7.html
+        to_der,
+        ffi::i2d_PKCS7
+    }
+
     /// Decrypts data using the provided private key.
     ///
     /// `pkey` is the recipient's private key, and `cert` is the recipient's