diff --git a/src/crypto/rsa/pkcs1v15.go b/src/crypto/rsa/pkcs1v15.go
index e51b9d2ca78..8a74862d801 100644
--- a/src/crypto/rsa/pkcs1v15.go
+++ b/src/crypto/rsa/pkcs1v15.go
@@ -252,6 +252,9 @@ var hashPrefixes = map[crypto.Hash][]byte{
 	crypto.SHA512:    {0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03, 0x05, 0x00, 0x04, 0x40},
 	crypto.MD5SHA1:   {}, // A special TLS case which doesn't use an ASN1 prefix.
 	crypto.RIPEMD160: {0x30, 0x20, 0x30, 0x08, 0x06, 0x06, 0x28, 0xcf, 0x06, 0x03, 0x00, 0x31, 0x04, 0x14},
+	crypto.SHA3_256:  {0x30, 0x31, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x08, 0x05, 0x00, 0x04, 0x20},
+	crypto.SHA3_384:  {0x30, 0x41, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x09, 0x05, 0x00, 0x04, 0x30},
+	crypto.SHA3_512:  {0x30, 0x51, 0x30, 0x0d, 0x06, 0x09, 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x0a, 0x05, 0x00, 0x04, 0x40},
 }
 
 // SignPKCS1v15 calculates the signature of hashed using