diff -aur tomcat-native-1.2.28-src/native/src/ssl.c tomcat-native-1.2.28-src.changed/native/src/ssl.c
--- tomcat-native-1.2.28-src/native/src/ssl.c	2021-04-01 06:28:54.000000000 -0700
+++ tomcat-native-1.2.28-src.changed/native/src/ssl.c	2021-05-20 13:21:18.569612200 -0700
@@ -367,6 +367,14 @@
 #endif
     free_dh_params();
 
+#ifndef OPENSSL_NO_ENGINE
+    if (tcn_ssl_engine != NULL) {
+        /* Release the SSL Engine structural reference */
+        ENGINE_free(tcn_ssl_engine);
+        tcn_ssl_engine = NULL;
+    }
+#endif
+
 #if OPENSSL_VERSION_NUMBER >= 0x10100000L && !defined(LIBRESSL_VERSION_NUMBER)
     /* Openssl v1.1+ handles all termination automatically. Do
      * nothing in this case.
@@ -815,9 +823,9 @@
                 if (!ENGINE_set_default(ee, ENGINE_METHOD_ALL))
                     err = APR_ENOTIMPL;
             }
-            /* Free our "structural" reference. */
+            /* Keep our "structural" reference. */
             if (ee)
-                ENGINE_free(ee);
+                tcn_ssl_engine = ee;
         }
         if (err != APR_SUCCESS) {
             TCN_FREE_CSTRING(engine);
@@ -825,7 +833,6 @@
             tcn_ThrowAPRException(e, err);
             return (jint)err;
         }
-        tcn_ssl_engine = ee;
     }
 #endif