diff --git a/Cargo.lock b/Cargo.lock
index 02627a8..691160e 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -458,6 +458,7 @@ dependencies = [
  "native-tls",
  "nom",
  "openssl",
+ "openssl-macros",
  "ouroboros",
  "regex",
  "rustls-connector",
diff --git a/Cargo.toml b/Cargo.toml
index 5e9e4de..52d7463 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -44,6 +44,7 @@ encoding = { version = "0.2.32", optional = true }
 failure = { version = "0.1.8", optional = true }
 mime = { version = "0.3.4", optional = true }
 openssl = { version = "0.10.60", optional = true }
+openssl-macros = { version = "0.1.1", optional = true }
 
 [[example]]
 name = "basic"