diff --git a/crypto/des/des.c b/crypto/des/des.c
index 6777de25..d1ddb7a3 100644
--- a/crypto/des/des.c
+++ b/crypto/des/des.c
@@ -638,6 +638,29 @@ void DES_ncbc_encrypt(const uint8_t *in, uint8_t *out, size_t len,
   tin[0] = tin[1] = 0;
 }
 
+void DES_ecb3_encrypt(const DES_cblock *input, DES_cblock *output,
+                      const DES_key_schedule *ks1, const DES_key_schedule *ks2,
+                      const DES_key_schedule *ks3, int enc) {
+  uint32_t l0, l1;
+  uint32_t ll[2];
+  const uint8_t *in = input->bytes;
+  uint8_t *out = output->bytes;
+
+  c2l(in, l0);
+  c2l(in, l1);
+  ll[0] = l0;
+  ll[1] = l1;
+  if (enc) {
+    DES_encrypt3(ll, ks1, ks2, ks3);
+  } else {
+    DES_decrypt3(ll, ks1, ks2, ks3);
+  }
+  l0 = ll[0];
+  l1 = ll[1];
+  l2c(l0, out);
+  l2c(l1, out);
+}
+
 void DES_ede3_cbc_encrypt(const uint8_t *in, uint8_t *out, size_t len,
                           const DES_key_schedule *ks1,
                           const DES_key_schedule *ks2,
diff --git a/include/openssl/des.h b/include/openssl/des.h
index 94188461..f3804c33 100644
--- a/include/openssl/des.h
+++ b/include/openssl/des.h
@@ -112,6 +112,15 @@ OPENSSL_EXPORT void DES_ncbc_encrypt(const uint8_t *in, uint8_t *out,
                                      const DES_key_schedule *schedule,
                                      DES_cblock *ivec, int enc);
 
+/* DES_ecb3_encrypt encrypts (or decrypts, if |enc| is |DES_DECRYPT|) a single
+ * block (8 bytes) of data from |input| to |output| using 3DES. */
+OPENSSL_EXPORT void DES_ecb3_encrypt(const DES_cblock *input,
+                                     DES_cblock *output,
+                                     const DES_key_schedule *ks1,
+                                     const DES_key_schedule *ks2,
+                                     const DES_key_schedule *ks3,
+                                     int enc);
+
 /* DES_ede3_cbc_encrypt encrypts (or decrypts, if |enc| is |DES_DECRYPT|) |len|
  * bytes from |in| to |out| with 3DES in CBC mode. 3DES uses three keys, thus
  * the function takes three different |DES_key_schedule|s. */