diff --git a/src/Psalm/Checker/Statements/Expression/Assignment/PropertyAssignmentChecker.php b/src/Psalm/Checker/Statements/Expression/Assignment/PropertyAssignmentChecker.php
index ea974935e..49a43e6c8 100644
--- a/src/Psalm/Checker/Statements/Expression/Assignment/PropertyAssignmentChecker.php
+++ b/src/Psalm/Checker/Statements/Expression/Assignment/PropertyAssignmentChecker.php
@@ -15,6 +15,7 @@ use Psalm\Issue\ImplicitToStringCast;
 use Psalm\Issue\InvalidPropertyAssignment;
 use Psalm\Issue\InvalidPropertyAssignmentValue;
 use Psalm\Issue\LoopInvalidation;
+use Psalm\Issue\MixedAssignment;
 use Psalm\Issue\MixedPropertyAssignment;
 use Psalm\Issue\MixedTypeCoercion;
 use Psalm\Issue\NoInterfaceProperties;
@@ -381,6 +382,18 @@ class PropertyAssignmentChecker
                         $lhs_type_part->value,
                         $lhs_type_part->value
                     );
+
+                    if (!$class_property_type->isMixed() && $assignment_value_type->isMixed()) {
+                        if (IssueBuffer::accepts(
+                            new MixedAssignment(
+                                'Cannot assign ' . $var_id . ' to a mixed type',
+                                new CodeLocation($statements_checker->getSource(), $stmt)
+                            ),
+                            $statements_checker->getSuppressedIssues()
+                        )) {
+                            // fall through
+                        }
+                    }
                 }
 
                 $class_property_types[] = $class_property_type;
diff --git a/src/Psalm/Checker/Statements/Expression/AssignmentChecker.php b/src/Psalm/Checker/Statements/Expression/AssignmentChecker.php
index 66dd033f2..273641c3e 100644
--- a/src/Psalm/Checker/Statements/Expression/AssignmentChecker.php
+++ b/src/Psalm/Checker/Statements/Expression/AssignmentChecker.php
@@ -172,14 +172,16 @@ class AssignmentChecker
         if ($assign_value_type->isMixed()) {
             $codebase->analyzer->incrementMixedCount($statements_checker->getCheckedFilePath());
 
-            if (IssueBuffer::accepts(
-                new MixedAssignment(
-                    'Cannot assign ' . $var_id . ' to a mixed type',
-                    new CodeLocation($statements_checker->getSource(), $assign_var)
-                ),
-                $statements_checker->getSuppressedIssues()
-            )) {
-                // fall through
+            if (!$assign_var instanceof PhpParser\Node\Expr\PropertyFetch) {
+                if (IssueBuffer::accepts(
+                    new MixedAssignment(
+                        'Cannot assign ' . $var_id . ' to a mixed type',
+                        new CodeLocation($statements_checker->getSource(), $assign_var)
+                    ),
+                    $statements_checker->getSuppressedIssues()
+                )) {
+                    // fall through
+                }
             }
         } else {
             $codebase->analyzer->incrementNonMixedCount($statements_checker->getCheckedFilePath());
diff --git a/tests/PropertyTypeTest.php b/tests/PropertyTypeTest.php
index f856cc229..f72d93100 100644
--- a/tests/PropertyTypeTest.php
+++ b/tests/PropertyTypeTest.php
@@ -828,6 +828,23 @@ class PropertyTypeTest extends TestCase
                         }
                     }',
             ],
+            'allowMixedAssignmetWhenDesired' => [
+                '<?php
+                    class A {
+                        /**
+                         * @var mixed
+                         */
+                        private $mixed;
+
+                        /**
+                         * @param mixed $value
+                         */
+                        public function setMixed($value): void
+                        {
+                            $this->mixed = $value;
+                        }
+                    }',
+            ],
         ];
     }
 
@@ -1270,6 +1287,24 @@ class PropertyTypeTest extends TestCase
                     }',
                 'error_message' => 'InvalidPropertyAssignmentValue',
             ],
+            'prohibitMixedAssignmentNormally' => [
+                '<?php
+                    class A {
+                        /**
+                         * @var string
+                         */
+                        private $mixed;
+
+                        /**
+                         * @param mixed $value
+                         */
+                        public function setMixed($value): void
+                        {
+                            $this->mixed = $value;
+                        }
+                    }',
+                'error_message' => 'MixedAssignment',
+            ],
         ];
     }
 }