diff --git a/openssl-sys/build.rs b/openssl-sys/build.rs
index b139811ef64ffe6627a8ec2b101f3017214bfd24..0af3f8ed74ceb8e7670d175871e46244a61c5d22 100644
--- a/openssl-sys/build.rs
+++ b/openssl-sys/build.rs
@@ -133,6 +133,9 @@ Could not find directory of OpenSSL installation, and this `-sys` crate cannot
 proceed without this knowledge. If OpenSSL is installed and this crate had
 trouble finding it,  you can set the `OPENSSL_DIR` environment variable for the
 compilation process.
+        
+Make sure you also have the development packages of openssl installed.
+For example, `libssl-dev` on Ubuntu or `openssl-devel` on Fedora.
 
 If you're in a situation where you think the directory *should* be found
 automatically, please open a bug at https://github.com/sfackler/rust-openssl