diff --git a/src/modules/ecdsa_adaptor/tests_impl.h b/src/modules/ecdsa_adaptor/tests_impl.h
index 3abc8127..c9bf0dac 100644
--- a/src/modules/ecdsa_adaptor/tests_impl.h
+++ b/src/modules/ecdsa_adaptor/tests_impl.h
@@ -1114,6 +1114,62 @@ static void multi_hop_lock_tests_internal(void) {
     CHECK(secp256k1_memcmp_var(buf, pop, 32) == 0);
 }
 
+static void adaptor_test_issue335(void) {
+    /* Inputs that will trigger R1==infinity in secp256k1_dleq_verify. */
+    unsigned char adaptor_sig[162] = {
+        0x03, 0x63, 0x3D, 0x56, 0xAB, 0xEE, 0x6F, 0x36, 0xE6, 0x07, 0xC6, 0x04,
+        0x2C, 0x68, 0xB4, 0x09, 0xBE, 0x4F, 0x3D, 0x56, 0x3A, 0x51, 0x7B, 0xCA,
+        0x95, 0xE6, 0xD9, 0x48, 0x1E, 0x95, 0xD0, 0xD6, 0xC6, 0x03, 0x91, 0x66,
+        0xC2, 0x89, 0xB9, 0xF9, 0x05, 0xE5, 0x5F, 0x9E, 0x3D, 0xF9, 0xF6, 0x9D,
+        0x7F, 0x35, 0x6B, 0x4A, 0x22, 0x09, 0x5F, 0x89, 0x4F, 0x47, 0x15, 0x71,
+        0x4A, 0xA4, 0xB5, 0x66, 0x06, 0xAF, 0x84, 0x40, 0xB2, 0x83, 0x34, 0xF6,
+        0x74, 0x18, 0xD8, 0x3D, 0x5C, 0xDC, 0x14, 0x0A, 0xAB, 0x22, 0x2B, 0x19,
+        0x15, 0x13, 0xC3, 0x5D, 0x9C, 0xBC, 0x6D, 0x89, 0x1C, 0xB5, 0x38, 0x74,
+        0xB0, 0xCE, 0x5F, 0x34, 0xD7, 0xA0, 0xA9, 0x89, 0x7A, 0x19, 0x45, 0x77,
+        0xBD, 0x5F, 0x0F, 0x31, 0xD8, 0x3B, 0x50, 0xC6, 0x2A, 0x4D, 0xCF, 0x4D,
+        0xCB, 0x91, 0x71, 0x8C, 0x66, 0xAE, 0xB8, 0xE2, 0x1A, 0x01, 0x65, 0x05,
+        0x2D, 0x93, 0x73, 0x97, 0xB7, 0x66, 0xC4, 0xEB, 0x23, 0x8D, 0x3B, 0x55,
+        0xA2, 0x3D, 0xF8, 0x8E, 0x56, 0x84, 0x87, 0x10, 0x76, 0x18, 0xC2, 0xE8,
+        0x35, 0xF9, 0x4E, 0x2A, 0x29, 0xB2
+    };
+    unsigned char msg[32] = {
+        0x38, 0x9C, 0x43, 0x7B, 0x37, 0xBB, 0x6F, 0x74, 0x09, 0x3D, 0x69,
+        0x3E, 0x3D, 0x9B, 0x4F, 0xC7, 0x9D, 0xDF, 0xA9, 0x33, 0x39, 0x8C,
+        0x90, 0x03, 0x95, 0x2D, 0x67, 0xCD, 0xD9, 0x99, 0xDC, 0x55
+    };
+    unsigned char deckey[32] = {
+        0x4A, 0x0B, 0x45, 0xA7, 0x4F, 0xBF, 0x49, 0xC3, 0x4B, 0x7C, 0xE0,
+        0x8E, 0x34, 0x89, 0xFB, 0xEA, 0xD5, 0x41, 0xA1, 0x2E, 0xBE, 0x13,
+        0x3F, 0xD6, 0x8E, 0x24, 0x86, 0x60, 0x1B, 0x19, 0xC1, 0xB5
+    };
+    unsigned char seckey[32] = {
+        0x12, 0xDB, 0x27, 0x33, 0x51, 0x3D, 0xD9, 0xDF, 0x6A, 0x3C, 0x5A,
+        0xEC, 0x3C, 0xA9, 0xF5, 0xDA, 0xA7, 0x3E, 0xB4, 0x61, 0xC8, 0xBB,
+        0x12, 0xB7, 0xD4, 0xAA, 0xF5, 0x9A, 0xE9, 0xE5, 0x8B, 0xB7
+    };
+    secp256k1_pubkey pubkey;
+    secp256k1_pubkey enckey;
+
+    CHECK(secp256k1_ec_pubkey_create(CTX, &pubkey, seckey) == 1);
+    CHECK(secp256k1_ec_pubkey_create(CTX, &enckey, deckey) == 1);
+    CHECK(secp256k1_ecdsa_adaptor_verify(CTX, adaptor_sig, &pubkey, msg, &enckey) == 0);
+
+    /* This explains how the inputs were obtained. */
+    {
+        unsigned char adaptor_sig_tmp[sizeof(adaptor_sig)];
+        /* Since the same nonce function with different algo arguments is used
+         * both for the adaptor sig secret nonce and the dleq secret nonce,
+         * but ecdsa_adaptor_nonce_function_overflowing ignores the algo arg
+         * (in violation of the documented API contract), the resulting secret
+         * nonces will be the same. */
+        CHECK(secp256k1_ecdsa_adaptor_encrypt(CTX, adaptor_sig_tmp, seckey, &enckey, msg, ecdsa_adaptor_nonce_function_overflowing, NULL) == 1);
+        CHECK(secp256k1_ecdsa_adaptor_verify(CTX, adaptor_sig_tmp, &pubkey, msg, &enckey) == 1);
+        /* Increment the last least significant bit of e. */
+        adaptor_sig_tmp[129] = 0x01;
+        CHECK(secp256k1_memcmp_var(adaptor_sig_tmp, adaptor_sig, sizeof(adaptor_sig)) == 0);
+    }
+}
+
 /* --- Test registry --- */
 REPEAT_TEST(dleq_tests)
 REPEAT_TEST(adaptor_tests)
@@ -1126,6 +1182,7 @@ static const struct tf_test_entry tests_ecdsa_adaptor[] = {
     CASE1(dleq_tests),
     CASE1(adaptor_tests),
     CASE1(multi_hop_lock_tests),
+    CASE1(adaptor_test_issue335),
 };
 
 #endif /* SECP256K1_MODULE_ECDSA_ADAPTOR_TESTS_H */