diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index c99a58a..1a51c42 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -6,6 +6,8 @@
 
 .. note:: This version is not yet released and is under active development.
 
+* Support for OpenSSL 1.0.0 has been removed. Users on older version of OpenSSL
+  will need to upgrade.
 
 1.6 - 2016-11-22
 ~~~~~~~~~~~~~~~~
diff --git a/docs/faq.rst b/docs/faq.rst
index 2ddc5db..76117a9 100644
--- a/docs/faq.rst
+++ b/docs/faq.rst
@@ -40,6 +40,19 @@
 appear to be at fault, it's possible that this is a bug in ``cryptography``.
 Please file an `issue`_ with instructions on how to reproduce it.
 
+Importing cryptography causes a ``RuntimeError`` about OpenSSL 1.0.0
+--------------------------------------------------------------------
+
+The OpenSSL project has dropped support for the 1.0.0 release series. Since it
+is no longer receiving security patches from upstream, ``cryptography`` is also
+dropping support for it. To fix this issue you should upgrade to a newer
+version of OpenSSL (1.0.1 or later). This may require you to upgrade to a newer
+operating system.
+
+For the 1.7 release, you can set the ``CRYPTOGRAPHY_ALLOW_OPENSSL_100``
+environment variable. Please note that this is *temporary* and will be removed
+in ``cryptography`` 1.8.
+
 Installing cryptography with OpenSSL 0.9.8 fails
 ------------------------------------------------
 
@@ -49,10 +62,6 @@
 version of OpenSSL (1.0.1 or later). This may require you to upgrade to a newer
 operating system.
 
-In ``cryptography`` 1.4, you can set the ``CRYPTOGRAPHY_ALLOW_OPENSSL_098``
-environment variable. Please note that this is *temporary* and is removed in
-``cryptography`` 1.5.
-
 .. _`NaCl`: https://nacl.cr.yp.to/
 .. _`PyNaCl`: https://pynacl.readthedocs.io
 .. _`WSGIApplicationGroup`: https://modwsgi.readthedocs.io/en/develop/configuration-directives/WSGIApplicationGroup.html
diff --git a/docs/installation.rst b/docs/installation.rst
index 724c63d..e1818d3 100644
--- a/docs/installation.rst
+++ b/docs/installation.rst
@@ -37,8 +37,8 @@
 * ``OpenSSL 1.1.0``
 
 .. warning::
-    OpenSSL 1.0.0 is no longer supported by the OpenSSL project. Cryptography
-    will drop support for it in the next release.
+    Cryptography 1.7 has dropped support for OpenSSL 1.0.0, see the
+    :doc:`FAQ </faq>` for more details
 
 Building cryptography on Windows
 --------------------------------
diff --git a/src/cryptography/hazmat/bindings/openssl/binding.py b/src/cryptography/hazmat/bindings/openssl/binding.py
index 25849bf..19151b0 100644
--- a/src/cryptography/hazmat/bindings/openssl/binding.py
+++ b/src/cryptography/hazmat/bindings/openssl/binding.py
@@ -191,12 +191,19 @@
 
 def _verify_openssl_version(version):
     if version < 0x10001000:
-        warnings.warn(
-            "OpenSSL version 1.0.0 is no longer supported by the OpenSSL "
-            "project, please upgrade. The next version of cryptography will "
-            "drop support for it.",
-            DeprecationWarning
-        )
+        if os.environ.get("CRYPTOGRAPHY_ALLOW_OPENSSL_100"):
+            warnings.warn(
+                "OpenSSL version 1.0.0 is no longer supported by the OpenSSL "
+                "project, please upgrade. The next version of cryptography "
+                "will completely remove support for it.",
+                DeprecationWarning
+            )
+        else:
+            raise RuntimeError(
+                "You are linking against OpenSSL 1.0.0, which is no longer "
+                "support by the OpenSSL project. You need to upgrade to a "
+                "newer version of OpenSSL."
+            )
 
 
 # OpenSSL is not thread safe until the locks are initialized. We call this
diff --git a/tests/hazmat/bindings/test_openssl.py b/tests/hazmat/bindings/test_openssl.py
index bbdd87c..3e01717 100644
--- a/tests/hazmat/bindings/test_openssl.py
+++ b/tests/hazmat/bindings/test_openssl.py
@@ -8,7 +8,7 @@
 
 from cryptography.exceptions import InternalError
 from cryptography.hazmat.bindings.openssl.binding import (
-    Binding, _OpenSSLErrorWithText, _openssl_assert
+    Binding, _OpenSSLErrorWithText, _openssl_assert, _verify_openssl_version
 )
 
 
@@ -107,3 +107,9 @@
                 b'ex:data not multiple of block length'
             )
         )]
+
+    def test_verify_openssl_version(self, monkeypatch):
+        monkeypatch.delenv("CRYPTOGRAPHY_ALLOW_OPENSSL_100", raising=False)
+        with pytest.raises(RuntimeError):
+            # OpenSSL 1.0.0
+            _verify_openssl_version(0x100000F)
diff --git a/tox.ini b/tox.ini
index 944ef85..ce80b18 100644
--- a/tox.ini
+++ b/tox.ini
@@ -8,6 +8,8 @@
     coverage
     ./vectors
 passenv = ARCHFLAGS LDFLAGS CFLAGS INCLUDE LIB LD_LIBRARY_PATH USERNAME
+setenv =
+    CRYPTOGRAPHY_ALLOW_OPENSSL_100=1
 commands =
     pip list
     # We use parallel mode and then combine here so that coverage.py will take