diff --git a/jni/jni_wolfssl_cert_manager.c b/jni/jni_wolfssl_cert_manager.c
index c14e33de..8a497ea9 100644
--- a/jni/jni_wolfssl_cert_manager.c
+++ b/jni/jni_wolfssl_cert_manager.c
@@ -369,13 +369,31 @@ JNIEXPORT jint JNICALL Java_com_wolfssl_wolfcrypt_WolfSSLCertManager_CertManager
         return (jint)BAD_FUNC_ARG;
     }
 
-    certFile = (*env)->GetStringUTFChars(env, f, 0);
-    certPath = (*env)->GetStringUTFChars(env, d, 0);
+    /* f and d are both optional, pass NULL through to native wolfSSL */
+    if (f != NULL) {
+        certFile = (*env)->GetStringUTFChars(env, f, 0);
+        if (certFile == NULL) {
+            return (jint)MEMORY_E;
+        }
+    }
+    if (d != NULL) {
+        certPath = (*env)->GetStringUTFChars(env, d, 0);
+        if (certPath == NULL) {
+            if (certFile != NULL) {
+                (*env)->ReleaseStringUTFChars(env, f, certFile);
+            }
+            return (jint)MEMORY_E;
+        }
+    }
 
     ret = wolfSSL_CertManagerLoadCA(cm, certFile, certPath);
 
-    (*env)->ReleaseStringUTFChars(env, f, certFile);
-    (*env)->ReleaseStringUTFChars(env, d, certPath);
+    if (certFile != NULL) {
+        (*env)->ReleaseStringUTFChars(env, f, certFile);
+    }
+    if (certPath != NULL) {
+        (*env)->ReleaseStringUTFChars(env, d, certPath);
+    }
 
     return (jint)ret;
 #else
diff --git a/src/test/java/com/wolfssl/wolfcrypt/test/WolfCryptTestSuite.java b/src/test/java/com/wolfssl/wolfcrypt/test/WolfCryptTestSuite.java
index f5b7b9ae..9b03a67a 100644
--- a/src/test/java/com/wolfssl/wolfcrypt/test/WolfCryptTestSuite.java
+++ b/src/test/java/com/wolfssl/wolfcrypt/test/WolfCryptTestSuite.java
@@ -58,6 +58,7 @@ import org.junit.runners.Suite.SuiteClasses;
     XmssTest.class,
     LmsTest.class,
     WolfObjectTest.class,
+    WolfSSLCertManagerTest.class,
     WolfSSLCertManagerOCSPTest.class,
     WolfSSLX509StoreCtxTest.class,
     WolfCryptTest.class
diff --git a/src/test/java/com/wolfssl/wolfcrypt/test/WolfSSLCertManagerTest.java b/src/test/java/com/wolfssl/wolfcrypt/test/WolfSSLCertManagerTest.java
new file mode 100644
index 00000000..e7da973b
--- /dev/null
+++ b/src/test/java/com/wolfssl/wolfcrypt/test/WolfSSLCertManagerTest.java
@@ -0,0 +1,133 @@
+/* WolfSSLCertManagerTest.java
+ *
+ * Copyright (C) 2006-2026 wolfSSL Inc.
+ *
+ * This file is part of wolfSSL.
+ *
+ * wolfSSL is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * wolfSSL is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1335, USA
+ */
+
+package com.wolfssl.wolfcrypt.test;
+
+import static org.junit.Assert.*;
+
+import org.junit.Assume;
+import org.junit.BeforeClass;
+import org.junit.Test;
+import org.junit.Rule;
+import org.junit.rules.TestRule;
+import org.junit.runners.model.Statement;
+import org.junit.runner.Description;
+
+import java.io.File;
+
+import com.wolfssl.wolfcrypt.WolfSSLCertManager;
+import com.wolfssl.wolfcrypt.WolfCryptError;
+import com.wolfssl.wolfcrypt.WolfCryptException;
+
+/**
+ * JUnit4 test cases for WolfSSLCertManager CA loading functionality.
+ */
+public class WolfSSLCertManagerTest {
+
+    private static String certPre = "";
+    private static String caCertPem = null;
+
+    @Rule(order = Integer.MIN_VALUE)
+    public TestRule testWatcher = TimedTestWatcher.create();
+
+    /* Rule to check if cert files are available, skips tests if not. */
+    @Rule(order = Integer.MIN_VALUE + 1)
+    public TestRule certFilesAvailable = new TestRule() {
+        @Override
+        public Statement apply(final Statement base,
+                               Description description) {
+            return new Statement() {
+                @Override
+                public void evaluate() throws Throwable {
+                    File f = new File(caCertPem);
+                    Assume.assumeTrue("Test cert files not available: " +
+                        caCertPem, f.exists());
+                    base.evaluate();
+                }
+            };
+        }
+    };
+
+    /**
+     * Test if this environment is Android.
+     * @return true if Android, otherwise false
+     */
+    private static boolean isAndroid() {
+        if (System.getProperty("java.runtime.name").contains("Android")) {
+            return true;
+        }
+        return false;
+    }
+
+    @BeforeClass
+    public static void testSetup() throws Exception {
+
+        System.out.println("JNI WolfSSLCertManager Class");
+
+        if (isAndroid()) {
+            /* On Android, example certs/keys are on SD card */
+            certPre = "/data/local/tmp/";
+        }
+
+        /* Set paths to example certs */
+        caCertPem = certPre.concat("examples/certs/ca-cert.pem");
+    }
+
+    @Test
+    public void testCertManagerLoadCAFromFileNullDir() throws Exception {
+
+        WolfSSLCertManager cm = new WolfSSLCertManager();
+
+        /* Directory argument is documented as optional, null should
+         * be passed through to native wolfSSL without error */
+        try {
+            cm.CertManagerLoadCA(caCertPem, null);
+
+        } catch (WolfCryptException e) {
+            if (e.getError() == WolfCryptError.NOT_COMPILED_IN) {
+                /* Skip test if filesystem support not compiled in */
+                Assume.assumeNoException(e);
+            }
+            throw e;
+
+        } finally {
+            cm.free();
+        }
+    }
+
+    @Test
+    public void testCertManagerLoadCANullFileNullDir() throws Exception {
+
+        WolfSSLCertManager cm = new WolfSSLCertManager();
+
+        /* Both arguments null should throw exception, not crash */
+        try {
+            cm.CertManagerLoadCA(null, null);
+            fail("CertManagerLoadCA(null, null) should throw exception");
+
+        } catch (WolfCryptException e) {
+            /* expected */
+
+        } finally {
+            cm.free();
+        }
+    }
+}