diff --git a/tests/RFC6978VectorTest.php b/tests/RFC6978VectorTest.php
index c9063fe4..9e849abe 100644
--- a/tests/RFC6978VectorTest.php
+++ b/tests/RFC6978VectorTest.php
@@ -50,15 +50,15 @@ public function theVectorsFromRFC6978CanBeVerified(
     }
 
     /** @return mixed[] */
-    public function dataRFC6979(): iterable
+    public static function dataRFC6979(): iterable
     {
-        yield from $this->sha256Data();
-        yield from $this->sha384Data();
-        yield from $this->sha512Data();
+        yield from self::sha256Data();
+        yield from self::sha384Data();
+        yield from self::sha512Data();
     }
 
     /** @return mixed[] */
-    public function sha256Data(): iterable
+    public static function sha256Data(): iterable
     {
         $signer = new Sha256();
         $key    = InMemory::plainText(
@@ -86,7 +86,7 @@ public function sha256Data(): iterable
     }
 
     /** @return mixed[] */
-    public function sha384Data(): iterable
+    public static function sha384Data(): iterable
     {
         $signer = new Sha384();
         $key    = InMemory::plainText(
@@ -115,7 +115,7 @@ public function sha384Data(): iterable
     }
 
     /** @return mixed[] */
-    public function sha512Data(): iterable
+    public static function sha512Data(): iterable
     {
         $signer = new Sha512();
         $key    = InMemory::plainText(
diff --git a/tests/Signer/Ecdsa/EcdsaTestCase.php b/tests/Signer/Ecdsa/EcdsaTestCase.php
index 9b16751e..06ac0568 100644
--- a/tests/Signer/Ecdsa/EcdsaTestCase.php
+++ b/tests/Signer/Ecdsa/EcdsaTestCase.php
@@ -118,7 +118,7 @@ public function signShouldRaiseAnExceptionWhenKeyLengthIsNotTheExpectedOne(
     }
 
     /** @return iterable<string, array{string, int}> */
-    abstract protected function incompatibleKeys(): iterable;
+    abstract public static function incompatibleKeys(): iterable;
 
     /** @test */
     public function signShouldRaiseAnExceptionWhenKeyTypeIsNotEC(): void
diff --git a/tests/Signer/Ecdsa/MultibyteStringConverterTest.php b/tests/Signer/Ecdsa/MultibyteStringConverterTest.php
index cd3ca8c4..eec52365 100644
--- a/tests/Signer/Ecdsa/MultibyteStringConverterTest.php
+++ b/tests/Signer/Ecdsa/MultibyteStringConverterTest.php
@@ -75,7 +75,7 @@ public function fromAsn1ShouldReturnTheConcatenatedPoints(string $r, string $s,
     }
 
     /** @return string[][] */
-    public function pointsConversionData(): iterable
+    public static function pointsConversionData(): iterable
     {
         return [
             [
@@ -125,7 +125,7 @@ public function fromAsn1ShouldRaiseExceptionOnInvalidMessage(string $message, st
     }
 
     /** @return string[][] */
-    public function invalidAsn1Structures(): iterable
+    public static function invalidAsn1Structures(): iterable
     {
         return [
             'Not a sequence'           => ['', 'Should start with a sequence'],
diff --git a/tests/Signer/Ecdsa/Sha256Test.php b/tests/Signer/Ecdsa/Sha256Test.php
index 0b5a36e2..e7bb4f33 100644
--- a/tests/Signer/Ecdsa/Sha256Test.php
+++ b/tests/Signer/Ecdsa/Sha256Test.php
@@ -56,7 +56,7 @@ protected function signingKey(): Key
     }
 
     /** {@inheritdoc} */
-    protected function incompatibleKeys(): iterable
+    public static function incompatibleKeys(): iterable
     {
         yield '384 bits' => ['private_ec384', 384];
         yield '521 bits' => ['private_ec512', 521];
diff --git a/tests/Signer/Ecdsa/Sha384Test.php b/tests/Signer/Ecdsa/Sha384Test.php
index d1083400..2a115c44 100644
--- a/tests/Signer/Ecdsa/Sha384Test.php
+++ b/tests/Signer/Ecdsa/Sha384Test.php
@@ -56,7 +56,7 @@ protected function signingKey(): Key
     }
 
     /** {@inheritdoc} */
-    protected function incompatibleKeys(): iterable
+    public static function incompatibleKeys(): iterable
     {
         yield '256 bits' => ['private', 256];
         yield '521 bits' => ['private_ec512', 521];
diff --git a/tests/Signer/Ecdsa/Sha512Test.php b/tests/Signer/Ecdsa/Sha512Test.php
index 2d5d8292..bfd14705 100644
--- a/tests/Signer/Ecdsa/Sha512Test.php
+++ b/tests/Signer/Ecdsa/Sha512Test.php
@@ -56,7 +56,7 @@ protected function signingKey(): Key
     }
 
     /** {@inheritdoc} */
-    protected function incompatibleKeys(): iterable
+    public static function incompatibleKeys(): iterable
     {
         yield '256 bits' => ['private', 256];
         yield '384 bits' => ['private_ec384', 384];
diff --git a/tests/SodiumBase64PolyfillTest.php b/tests/SodiumBase64PolyfillTest.php
index c33453aa..74a893de 100644
--- a/tests/SodiumBase64PolyfillTest.php
+++ b/tests/SodiumBase64PolyfillTest.php
@@ -104,7 +104,7 @@ public function base642binFallback(int $variant): void
     }
 
     /** @return int[][] */
-    public function provideVariants(): array
+    public static function provideVariants(): array
     {
         return [
             [SODIUM_BASE64_VARIANT_ORIGINAL],
diff --git a/tests/TimeFractionPrecisionTest.php b/tests/TimeFractionPrecisionTest.php
index ba61a27c..80058c7f 100644
--- a/tests/TimeFractionPrecisionTest.php
+++ b/tests/TimeFractionPrecisionTest.php
@@ -57,7 +57,7 @@ public function timeFractionsPrecisionsAreRespected(string $timeFraction): void
     }
 
     /** @return iterable<string[]> */
-    public function datesWithPotentialRoundingIssues(): iterable
+    public static function datesWithPotentialRoundingIssues(): iterable
     {
         yield ['1613938511.017448'];
         yield ['1613938511.023691'];
@@ -86,7 +86,7 @@ public function typeConversionDoesNotCauseParsingErrors(float|int|string $issued
     }
 
     /** @return iterable<array{0: float|int|string, 1: string}> */
-    public function timeFractionConversions(): iterable
+    public static function timeFractionConversions(): iterable
     {
         yield [1616481863.528781890869140625, '1616481863.528782'];
         yield [1616497608.0510409, '1616497608.051041'];
diff --git a/tests/Validation/Constraint/HasClaimWithValueTest.php b/tests/Validation/Constraint/HasClaimWithValueTest.php
index 3c083316..bf7a1b78 100644
--- a/tests/Validation/Constraint/HasClaimWithValueTest.php
+++ b/tests/Validation/Constraint/HasClaimWithValueTest.php
@@ -37,7 +37,7 @@ public function registeredClaimsCannotBeValidatedUsingThisConstraint(string $cla
     }
 
     /** @return iterable<non-empty-string, array{non-empty-string}> */
-    public function registeredClaims(): iterable
+    public static function registeredClaims(): iterable
     {
         foreach (Token\RegisteredClaims::ALL as $claim) {
             yield $claim => [$claim];