diff --git a/src/Analyser/MutatingScope.php b/src/Analyser/MutatingScope.php
index 7c97dfe518..1b48497491 100644
--- a/src/Analyser/MutatingScope.php
+++ b/src/Analyser/MutatingScope.php
@@ -87,6 +87,7 @@
 use PHPStan\Type\UnionType;
 use PHPStan\Type\VerbosityLevel;
 use PHPStan\Type\VoidType;
+use function array_key_exists;
 
 class MutatingScope implements Scope
 {
@@ -2269,7 +2270,8 @@ public function enterClassMethod(
 				$isDeprecated,
 				$isInternal,
 				$isFinal
-			)
+			),
+			!$classMethod->isStatic()
 		);
 	}
 
@@ -2354,12 +2356,14 @@ public function enterFunction(
 				$isDeprecated,
 				$isInternal,
 				$isFinal
-			)
+			),
+			false
 		);
 	}
 
 	private function enterFunctionLike(
-		PhpFunctionFromParserNodeReflection $functionReflection
+		PhpFunctionFromParserNodeReflection $functionReflection,
+		bool $preserveThis
 	): self
 	{
 		$variableTypes = $this->getVariableTypes();
@@ -2373,6 +2377,10 @@ private function enterFunctionLike(
 			$nativeExpressionTypes[sprintf('$%s', $parameter->getName())] = $parameter->getNativeType();
 		}
 
+		if (!$preserveThis && array_key_exists('this', $variableTypes)) {
+			unset($variableTypes['this']);
+		}
+
 		return $this->scopeFactory->create(
 			$this->context,
 			$this->isDeclareStrictTypes(),
diff --git a/tests/PHPStan/Rules/Variables/DefinedVariableRuleTest.php b/tests/PHPStan/Rules/Variables/DefinedVariableRuleTest.php
index 0967819bb3..d82872d89e 100644
--- a/tests/PHPStan/Rules/Variables/DefinedVariableRuleTest.php
+++ b/tests/PHPStan/Rules/Variables/DefinedVariableRuleTest.php
@@ -744,4 +744,50 @@ public function testRootScopeMaybeDefined(): void
 		$this->analyse([__DIR__ . '/data/root-scope-maybe.php'], []);
 	}
 
+	public function testRootScopeMaybeDefinedCheck(): void
+	{
+		$this->cliArgumentsVariablesRegistered = true;
+		$this->polluteScopeWithLoopInitialAssignments = false;
+		$this->polluteCatchScopeWithTryAssignments = false;
+		$this->checkMaybeUndefinedVariables = true;
+		$this->polluteScopeWithAlwaysIterableForeach = true;
+		$this->analyse([__DIR__ . '/data/root-scope-maybe.php'], [
+			[
+				'Variable $maybe might not be defined.',
+				3,
+			],
+			[
+				'Variable $this might not be defined.',
+				5,
+			],
+		]);
+	}
+
+	public function testFormerThisVariableRule(): void
+	{
+		$this->cliArgumentsVariablesRegistered = true;
+		$this->polluteScopeWithLoopInitialAssignments = false;
+		$this->polluteCatchScopeWithTryAssignments = false;
+		$this->checkMaybeUndefinedVariables = true;
+		$this->polluteScopeWithAlwaysIterableForeach = true;
+		$this->analyse([__DIR__ . '/data/this.php'], [
+			[
+				'Undefined variable: $this',
+				16,
+			],
+			[
+				'Undefined variable: $this',
+				20,
+			],
+			[
+				'Undefined variable: $this',
+				26,
+			],
+			[
+				'Undefined variable: $this',
+				38,
+			],
+		]);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Variables/data/root-scope-maybe.php b/tests/PHPStan/Rules/Variables/data/root-scope-maybe.php
index 58c84f167b..9bfaf528a8 100644
--- a/tests/PHPStan/Rules/Variables/data/root-scope-maybe.php
+++ b/tests/PHPStan/Rules/Variables/data/root-scope-maybe.php
@@ -1,3 +1,5 @@
 <?php
 
 echo $maybe;
+
+echo $this;
diff --git a/tests/PHPStan/Rules/Variables/data/this.php b/tests/PHPStan/Rules/Variables/data/this.php
index ac79b9179d..1c71aca1f3 100644
--- a/tests/PHPStan/Rules/Variables/data/this.php
+++ b/tests/PHPStan/Rules/Variables/data/this.php
@@ -8,14 +8,14 @@ class Foo
 	public function doFoo()
 	{
 		$this->test;
-		$foo->test;
+
 	}
 
 	public static function doBar()
 	{
 		$this->test;
-		$foo->test;
-		$$bar->test;
+
+
 
 		$this->blabla = 'fooo';
 	}