diff --git a/changes/bug16901 b/changes/bug16901
new file mode 100644
index 0000000000000000000000000000000000000000..c008ebdbd862a3dc506ec5f87f53e060fc4ac095
--- /dev/null
+++ b/changes/bug16901
@@ -0,0 +1,3 @@
+  o Minor features (compilation):
+    - Give a warning as early as possible when trying to build with an
+      unsupported OpenSSL version.  Closes ticket 16901.
diff --git a/configure.ac b/configure.ac
index 3bb70ed88fc3d8daec8e00486225498e3eb0ba24..984a7084b3bec4519c47803aab6de9dc38160eb9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -632,6 +632,16 @@ save_CPPFLAGS="$CPPFLAGS"
 LIBS="$TOR_OPENSSL_LIBS $LIBS"
 LDFLAGS="$TOR_LDFLAGS_openssl $LDFLAGS"
 CPPFLAGS="$TOR_CPPFLAGS_openssl $CPPFLAGS"
+
+AC_TRY_COMPILE([
+#include <openssl/opensslv.h>
+#if OPENSSL_VERSION_NUMBER < 0x1000000fL
+#error "too old"
+#endif
+   ], [],
+   [ ],
+   [ AC_ERROR([OpenSSL is too old. We require 1.0.0 or later. You can specify a path to a newer one with --with-openssl-dir.]) ])
+
 AC_CHECK_MEMBERS([struct ssl_method_st.get_cipher_by_char], , ,
 [#include <openssl/ssl.h>
 ])