diff --git a/src/Crypto/EcAdapter/Impl/Secp256k1/Adapter/EcAdapter.php b/src/Crypto/EcAdapter/Impl/Secp256k1/Adapter/EcAdapter.php
index 334806d81..49494d53e 100644
--- a/src/Crypto/EcAdapter/Impl/Secp256k1/Adapter/EcAdapter.php
+++ b/src/Crypto/EcAdapter/Impl/Secp256k1/Adapter/EcAdapter.php
@@ -44,7 +44,7 @@ class EcAdapter implements EcAdapterInterface
      */
     public function __construct(Math $math, GeneratorPoint $generator, $secp256k1_context_t)
     {
-        if (!is_resource($secp256k1_context_t) || !get_resource_type($secp256k1_context_t) === SECP256K1_TYPE_CONTEXT) {
+        if (!is_resource($secp256k1_context_t) || get_resource_type($secp256k1_context_t) !== SECP256K1_TYPE_CONTEXT) {
             throw new \InvalidArgumentException('Secp256k1: Must pass a secp256k1_context_t resource');
         }
 
diff --git a/src/Crypto/EcAdapter/Impl/Secp256k1/Key/PublicKey.php b/src/Crypto/EcAdapter/Impl/Secp256k1/Key/PublicKey.php
index 649bf55af..4db7ab3d4 100644
--- a/src/Crypto/EcAdapter/Impl/Secp256k1/Key/PublicKey.php
+++ b/src/Crypto/EcAdapter/Impl/Secp256k1/Key/PublicKey.php
@@ -38,8 +38,7 @@ class PublicKey extends Key implements PublicKeyInterface
      */
     public function __construct(EcAdapter $ecAdapter, $secp256k1_pubkey_t, bool $compressed = false)
     {
-        if (!is_resource($secp256k1_pubkey_t) ||
-            !get_resource_type($secp256k1_pubkey_t) === SECP256K1_TYPE_PUBKEY) {
+        if (!is_resource($secp256k1_pubkey_t) || get_resource_type($secp256k1_pubkey_t) !== SECP256K1_TYPE_PUBKEY) {
             throw new \InvalidArgumentException('Secp256k1\Key\PublicKey expects ' . SECP256K1_TYPE_PUBKEY . ' resource');
         }
 
diff --git a/src/Crypto/EcAdapter/Impl/Secp256k1/Signature/CompactSignature.php b/src/Crypto/EcAdapter/Impl/Secp256k1/Signature/CompactSignature.php
index 7a80c2219..e0bb0f09a 100644
--- a/src/Crypto/EcAdapter/Impl/Secp256k1/Signature/CompactSignature.php
+++ b/src/Crypto/EcAdapter/Impl/Secp256k1/Signature/CompactSignature.php
@@ -39,9 +39,7 @@ class CompactSignature extends Signature implements CompactSignatureInterface
      */
     public function __construct(EcAdapter $ecAdapter, $secp256k1_ecdsa_signature_t, int $recid, bool $compressed)
     {
-        if (!is_resource($secp256k1_ecdsa_signature_t)
-            || SECP256K1_TYPE_RECOVERABLE_SIG !== get_resource_type($secp256k1_ecdsa_signature_t)
-        ) {
+        if (!is_resource($secp256k1_ecdsa_signature_t) || SECP256K1_TYPE_RECOVERABLE_SIG !== get_resource_type($secp256k1_ecdsa_signature_t)) {
             throw new \RuntimeException('CompactSignature: must pass recoverable signature resource');
         }
 
diff --git a/src/Crypto/EcAdapter/Impl/Secp256k1/Signature/Signature.php b/src/Crypto/EcAdapter/Impl/Secp256k1/Signature/Signature.php
index b792414cc..e363cd05c 100644
--- a/src/Crypto/EcAdapter/Impl/Secp256k1/Signature/Signature.php
+++ b/src/Crypto/EcAdapter/Impl/Secp256k1/Signature/Signature.php
@@ -40,9 +40,7 @@ class Signature extends Serializable implements SignatureInterface
      */
     public function __construct(EcAdapter $adapter, \GMP $r, \GMP $s, $secp256k1_ecdsa_signature_t)
     {
-        if (!is_resource($secp256k1_ecdsa_signature_t) ||
-            !get_resource_type($secp256k1_ecdsa_signature_t) === SECP256K1_TYPE_SIG
-        ) {
+        if (!is_resource($secp256k1_ecdsa_signature_t) || get_resource_type($secp256k1_ecdsa_signature_t) !== SECP256K1_TYPE_SIG) {
             throw new \InvalidArgumentException('Secp256k1\Signature\Signature expects ' . SECP256K1_TYPE_SIG . ' resource');
         }
 
diff --git a/tests/Crypto/EcAdapter/Impl/Secp256k1/Adapter/EcAdapterTest.php b/tests/Crypto/EcAdapter/Impl/Secp256k1/Adapter/EcAdapterTest.php
new file mode 100644
index 000000000..2adf4f660
--- /dev/null
+++ b/tests/Crypto/EcAdapter/Impl/Secp256k1/Adapter/EcAdapterTest.php
@@ -0,0 +1,37 @@
+<?php declare(strict_types=1);
+
+namespace BitWasp\Bitcoin\Tests\Crypto\EcAdapter\Impl\Secp256k1\Adapter;
+
+use BitWasp\Bitcoin\Bitcoin;
+use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\Secp256k1\Adapter\EcAdapter;
+use BitWasp\Bitcoin\Math\Math;
+use BitWasp\Bitcoin\Tests\AbstractTestCase;
+
+class EcAdapterTest extends AbstractTestCase
+{
+    private function callConstructor($value)
+    {
+        $math = new Math();
+        $G = Bitcoin::getGenerator();
+        return new EcAdapter($math, $G, $value);
+    }
+    public function testContextNotResource()
+    {
+        if (!function_exists('secp256k1_context_create')) {
+            $this->markTestSkipped("secp256k1 not installed");
+        }
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage("Secp256k1: Must pass a secp256k1_context_t resource");
+        $this->callConstructor("");
+    }
+    public function testContextWrongResource()
+    {
+        if (!function_exists('secp256k1_context_create')) {
+            $this->markTestSkipped("secp256k1 not installed");
+        }
+        $ctx = gmp_init(1);
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage("Secp256k1: Must pass a secp256k1_context_t resource");
+        $this->callConstructor($ctx);
+    }
+}
\ No newline at end of file
diff --git a/tests/Crypto/EcAdapter/Impl/Secp256k1/Key/PublicKeyTest.php b/tests/Crypto/EcAdapter/Impl/Secp256k1/Key/PublicKeyTest.php
new file mode 100644
index 000000000..52c43d14a
--- /dev/null
+++ b/tests/Crypto/EcAdapter/Impl/Secp256k1/Key/PublicKeyTest.php
@@ -0,0 +1,36 @@
+<?php declare(strict_types=1);
+
+namespace BitWasp\Bitcoin\Tests\Crypto\EcAdapter\Impl\Secp256k1\Key;
+
+use BitWasp\Bitcoin\Bitcoin;
+use BitWasp\Bitcoin\Crypto\EcAdapter\EcAdapterFactory;
+use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\Secp256k1\Adapter\EcAdapter;
+use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\Secp256k1\Key\PublicKey;
+use BitWasp\Bitcoin\Math\Math;
+use BitWasp\Bitcoin\Tests\AbstractTestCase;
+
+class PublicKeyTest extends AbstractTestCase
+{
+    private function callConstructor($value)
+    {
+        return new PublicKey(EcAdapterFactory::getSecp256k1(new Math(), Bitcoin::getGenerator()), $value, true);
+    }
+    public function testNotResource()
+    {
+        if (!function_exists('secp256k1_context_create')) {
+            $this->markTestSkipped("secp256k1 not installed");
+        }
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Secp256k1\Key\PublicKey expects ' . SECP256K1_TYPE_PUBKEY . ' resource');
+        $this->callConstructor("");
+    }
+    public function testWrongResourceType()
+    {
+        if (!function_exists('secp256k1_context_create')) {
+            $this->markTestSkipped("secp256k1 not installed");
+        }
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('Secp256k1\Key\PublicKey expects ' . SECP256K1_TYPE_PUBKEY . ' resource');
+        $this->callConstructor(gmp_init(1));
+    }
+}
\ No newline at end of file
diff --git a/tests/Crypto/EcAdapter/Impl/Secp256k1/Signature/CompactSignatureTest.php b/tests/Crypto/EcAdapter/Impl/Secp256k1/Signature/CompactSignatureTest.php
new file mode 100644
index 000000000..2b9f40ad8
--- /dev/null
+++ b/tests/Crypto/EcAdapter/Impl/Secp256k1/Signature/CompactSignatureTest.php
@@ -0,0 +1,36 @@
+<?php declare(strict_types=1);
+
+namespace BitWasp\Bitcoin\Tests\Crypto\EcAdapter\Impl\Secp256k1\Signature;
+
+use BitWasp\Bitcoin\Bitcoin;
+use BitWasp\Bitcoin\Crypto\EcAdapter\EcAdapterFactory;
+use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\Secp256k1\Signature\CompactSignature;
+use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\Secp256k1\Signature\Signature;
+use BitWasp\Bitcoin\Math\Math;
+use BitWasp\Bitcoin\Tests\AbstractTestCase;
+
+class CompactSignatureTest extends AbstractTestCase
+{
+    private function callConstructor($value)
+    {
+        return new CompactSignature(EcAdapterFactory::getSecp256k1(new Math(), Bitcoin::getGenerator()), $value, 1, true);
+    }
+    public function testNotResource()
+    {
+        if (!function_exists('secp256k1_context_create')) {
+            $this->markTestSkipped("secp256k1 not installed");
+        }
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('CompactSignature: must pass recoverable signature resource');
+        $this->callConstructor("");
+    }
+    public function testWrongResourceType()
+    {
+        if (!function_exists('secp256k1_context_create')) {
+            $this->markTestSkipped("secp256k1 not installed");
+        }
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('CompactSignature: must pass recoverable signature resource');
+        $this->callConstructor(gmp_init(1));
+    }
+}
\ No newline at end of file
diff --git a/tests/Crypto/EcAdapter/Impl/Secp256k1/Signature/SignatureTest.php b/tests/Crypto/EcAdapter/Impl/Secp256k1/Signature/SignatureTest.php
new file mode 100644
index 000000000..0a92ba032
--- /dev/null
+++ b/tests/Crypto/EcAdapter/Impl/Secp256k1/Signature/SignatureTest.php
@@ -0,0 +1,35 @@
+<?php declare(strict_types=1);
+
+namespace BitWasp\Bitcoin\Tests\Crypto\EcAdapter\Impl\Secp256k1\Signature;
+
+use BitWasp\Bitcoin\Bitcoin;
+use BitWasp\Bitcoin\Crypto\EcAdapter\EcAdapterFactory;
+use BitWasp\Bitcoin\Crypto\EcAdapter\Impl\Secp256k1\Signature\Signature;
+use BitWasp\Bitcoin\Math\Math;
+use BitWasp\Bitcoin\Tests\AbstractTestCase;
+
+class SignatureTest extends AbstractTestCase
+{
+    private function callConstructor($value)
+    {
+        return new Signature(EcAdapterFactory::getSecp256k1(new Math(), Bitcoin::getGenerator()), gmp_init(1), gmp_init(1), $value);
+    }
+    public function testNotResource()
+    {
+        if (!function_exists('secp256k1_context_create')) {
+            $this->markTestSkipped("secp256k1 not installed");
+        }
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('CompactSignature: must pass recoverable signature resource');
+        $this->callConstructor("");
+    }
+    public function testWrongResourceType()
+    {
+        if (!function_exists('secp256k1_context_create')) {
+            $this->markTestSkipped("secp256k1 not installed");
+        }
+        $this->expectException(\InvalidArgumentException::class);
+        $this->expectExceptionMessage('CompactSignature: must pass recoverable signature resource');
+        $this->callConstructor(gmp_init(1));
+    }
+}
\ No newline at end of file