diff --git a/SlevomatCodingStandard/Sniffs/TypeHints/TypeHintDeclarationSniff.php b/SlevomatCodingStandard/Sniffs/TypeHints/TypeHintDeclarationSniff.php
index 9b45ba7f8..d3f13a734 100644
--- a/SlevomatCodingStandard/Sniffs/TypeHints/TypeHintDeclarationSniff.php
+++ b/SlevomatCodingStandard/Sniffs/TypeHints/TypeHintDeclarationSniff.php
@@ -192,8 +192,20 @@ private function checkParametersTypeHints(\PHP_CodeSniffer_File $phpcsFile, int
 					}
 				} elseif ($this->definitionContainsTraversableTypeHint($phpcsFile, $functionPointer, $parameterTypeHintDefinition)) {
 					$parameterTypeHintDefinitionParts = explode('|', $parameterTypeHintDefinition);
-					$possibleParameterTypeHint = $this->isTraversableTypeHint(TypeHintHelper::getFullyQualifiedTypeHint($phpcsFile, $functionPointer, $parameterTypeHintDefinitionParts[0])) ? $parameterTypeHintDefinitionParts[0] : $parameterTypeHintDefinitionParts[1];
 					$nullableParameterTypeHint = false;
+
+					if ($this->isTraversableTypeHint(TypeHintHelper::getFullyQualifiedTypeHint($phpcsFile, $functionPointer, $parameterTypeHintDefinitionParts[0]))) {
+						$possibleParameterTypeHint = $parameterTypeHintDefinitionParts[0];
+						$itemsTypeHintDefinition = $parameterTypeHintDefinitionParts[1];
+					} else {
+						$possibleParameterTypeHint = $parameterTypeHintDefinitionParts[1];
+						$itemsTypeHintDefinition = $parameterTypeHintDefinitionParts[0];
+					}
+
+					if (!$this->definitionContainsTraversableTypeHintSpeficication($itemsTypeHintDefinition)) {
+						return;
+					}
+
 				} else {
 					return;
 				}
@@ -398,8 +410,20 @@ private function checkReturnTypeHints(\PHP_CodeSniffer_File $phpcsFile, int $fun
 				}
 			} elseif ($this->definitionContainsTraversableTypeHint($phpcsFile, $functionPointer, $returnTypeHintDefinition)) {
 				$returnTypeHintDefinitionParts = explode('|', $returnTypeHintDefinition);
-				$possibleReturnTypeHint = $this->isTraversableTypeHint(TypeHintHelper::getFullyQualifiedTypeHint($phpcsFile, $functionPointer, $returnTypeHintDefinitionParts[0])) ? $returnTypeHintDefinitionParts[0] : $returnTypeHintDefinitionParts[1];
 				$nullableReturnTypeHint = false;
+
+				if ($this->isTraversableTypeHint(TypeHintHelper::getFullyQualifiedTypeHint($phpcsFile, $functionPointer, $returnTypeHintDefinitionParts[0]))) {
+					$possibleReturnTypeHint = $returnTypeHintDefinitionParts[0];
+					$itemsTypeHintDefinition = $returnTypeHintDefinitionParts[1];
+				} else {
+					$possibleReturnTypeHint = $returnTypeHintDefinitionParts[1];
+					$itemsTypeHintDefinition = $returnTypeHintDefinitionParts[0];
+				}
+
+				if (!$this->definitionContainsTraversableTypeHintSpeficication($itemsTypeHintDefinition)) {
+					return;
+				}
+
 			} else {
 				return;
 			}
diff --git a/tests/Sniffs/TypeHints/data/typeHintDeclarationNoErrors.php b/tests/Sniffs/TypeHints/data/typeHintDeclarationNoErrors.php
index 533b0775f..aa9bd1ba9 100644
--- a/tests/Sniffs/TypeHints/data/typeHintDeclarationNoErrors.php
+++ b/tests/Sniffs/TypeHints/data/typeHintDeclarationNoErrors.php
@@ -554,4 +554,21 @@ private function nullableMultidimensionalArrayParameter($a)
 	 */
 	abstract public function invalidAnnotations();
 
+	/**
+	 * @phpcsSuppress SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableParameterTypeHintSpecification
+	 * @param string|array $a
+	 */
+	public function mixedContainingTraversable($a)
+	{
+	}
+
+	/**
+	 * @phpcsSuppress SlevomatCodingStandard.TypeHints.TypeHintDeclaration.MissingTraversableReturnTypeHintSpecification
+	 * @return string|array
+	 */
+	public function returnsMixedContainingTraversable()
+	{
+		return [];
+	}
+
 }