diff --git a/src/Analyser/MutatingScope.php b/src/Analyser/MutatingScope.php
index 900c3f3fff..4e510b52f4 100644
--- a/src/Analyser/MutatingScope.php
+++ b/src/Analyser/MutatingScope.php
@@ -4094,6 +4094,14 @@ private function createConditionalExpressions(
 				continue;
 			}
 
+			if (
+				array_key_exists($exprString, $newVariableTypes)
+				&& !$newVariableTypes[$exprString]->getCertainty()->equals($holder->getCertainty())
+				&& $newVariableTypes[$exprString]->equalTypes($holder)
+			) {
+				continue;
+			}
+
 			unset($newVariableTypes[$exprString]);
 		}
 
diff --git a/src/Reflection/BetterReflection/SourceLocator/OptimizedDirectorySourceLocator.php b/src/Reflection/BetterReflection/SourceLocator/OptimizedDirectorySourceLocator.php
index e66dfea5d6..f2b0f7e3a6 100644
--- a/src/Reflection/BetterReflection/SourceLocator/OptimizedDirectorySourceLocator.php
+++ b/src/Reflection/BetterReflection/SourceLocator/OptimizedDirectorySourceLocator.php
@@ -127,7 +127,7 @@ public function locateIdentifier(Reflector $reflector, Identifier $identifier):
 				return null;
 			}
 
-			[$reflectionCacheKey, $variableCacheKey] = $this->getCacheKeys($file, $identifier); // @phpstan-ignore variable.undefined
+			[$reflectionCacheKey, $variableCacheKey] = $this->getCacheKeys($file, $identifier);
 			$classReflection = $this->nodeToReflection($reflector, $fetchedClassNode);
 			$this->cache->save($reflectionCacheKey, $variableCacheKey, $classReflection->exportToCache());
 
@@ -171,7 +171,7 @@ public function locateIdentifier(Reflector $reflector, Identifier $identifier):
 				return null;
 			}
 
-			[$reflectionCacheKey, $variableCacheKey] = $this->getCacheKeys($file, $identifier); // @phpstan-ignore variable.undefined
+			[$reflectionCacheKey, $variableCacheKey] = $this->getCacheKeys($file, $identifier);
 			$constantReflection = $this->nodeToReflection(
 				$reflector,
 				$fetchedConstantNode,
diff --git a/tests/PHPStan/Rules/Variables/DefinedVariableRuleTest.php b/tests/PHPStan/Rules/Variables/DefinedVariableRuleTest.php
index 1a9f84f7ab..d6a4ce9a4c 100644
--- a/tests/PHPStan/Rules/Variables/DefinedVariableRuleTest.php
+++ b/tests/PHPStan/Rules/Variables/DefinedVariableRuleTest.php
@@ -1323,6 +1323,26 @@ public function testBug5919(): void
 		$this->analyse([__DIR__ . '/data/bug-5919.php'], []);
 	}
 
+	public function testBug8430(): void
+	{
+		$this->cliArgumentsVariablesRegistered = true;
+		$this->polluteScopeWithLoopInitialAssignments = false;
+		$this->checkMaybeUndefinedVariables = true;
+		$this->polluteScopeWithAlwaysIterableForeach = true;
+
+		$this->analyse([__DIR__ . '/data/bug-8430.php'], []);
+	}
+
+	public function testBug8430b(): void
+	{
+		$this->cliArgumentsVariablesRegistered = true;
+		$this->polluteScopeWithLoopInitialAssignments = false;
+		$this->checkMaybeUndefinedVariables = true;
+		$this->polluteScopeWithAlwaysIterableForeach = true;
+
+		$this->analyse([__DIR__ . '/data/bug-8430b.php'], []);
+	}
+
 	public function testBug5477(): void
 	{
 		$this->cliArgumentsVariablesRegistered = true;
@@ -1333,4 +1353,51 @@ public function testBug5477(): void
 		$this->analyse([__DIR__ . '/data/bug-5477.php'], []);
 	}
 
+	public function testBug10657(): void
+	{
+		$this->cliArgumentsVariablesRegistered = true;
+		$this->polluteScopeWithLoopInitialAssignments = false;
+		$this->checkMaybeUndefinedVariables = true;
+		$this->polluteScopeWithAlwaysIterableForeach = true;
+
+		$this->analyse([__DIR__ . '/data/bug-10657.php'], []);
+	}
+
+	public function testBug6830(): void
+	{
+		$this->cliArgumentsVariablesRegistered = true;
+		$this->polluteScopeWithLoopInitialAssignments = false;
+		$this->checkMaybeUndefinedVariables = true;
+		$this->polluteScopeWithAlwaysIterableForeach = true;
+
+		$this->analyse([__DIR__ . '/data/bug-6830.php'], []);
+	}
+
+	public function testBug14117(): void
+	{
+		$this->cliArgumentsVariablesRegistered = true;
+		$this->polluteScopeWithLoopInitialAssignments = false;
+		$this->checkMaybeUndefinedVariables = true;
+		$this->polluteScopeWithAlwaysIterableForeach = true;
+
+		$this->analyse([__DIR__ . '/data/bug-14117.php'], [
+			[
+				'Variable $value might not be defined.',
+				33,
+			],
+			[
+				'Variable $value might not be defined.',
+				49,
+			],
+			[
+				'Undefined variable: $value',
+				65,
+			],
+			[
+				'Undefined variable: $value',
+				81,
+			],
+		]);
+	}
+
 }
diff --git a/tests/PHPStan/Rules/Variables/data/bug-10657.php b/tests/PHPStan/Rules/Variables/data/bug-10657.php
new file mode 100644
index 0000000000..f9d6a508fb
--- /dev/null
+++ b/tests/PHPStan/Rules/Variables/data/bug-10657.php
@@ -0,0 +1,18 @@
+<?php
+
+namespace Bug10657;
+
+class HelloWorld
+{
+	public function sayHello(bool $flag): void
+	{
+		for ($i = 0; $i < 10; $i++) {
+			if ($flag) {
+				$foo = 'bar';
+			}
+			if ($flag) {
+				echo $foo;
+			}
+		}
+	}
+}
diff --git a/tests/PHPStan/Rules/Variables/data/bug-14117.php b/tests/PHPStan/Rules/Variables/data/bug-14117.php
new file mode 100644
index 0000000000..e1d7c40306
--- /dev/null
+++ b/tests/PHPStan/Rules/Variables/data/bug-14117.php
@@ -0,0 +1,83 @@
+<?php declare(strict_types = 1);
+
+namespace Bug14117;
+
+function foo(): void {
+	$key = rand(0, 2);
+
+	if ($key === 2) {
+		$value = 'test';
+	}
+
+	if ($key === 1) {
+		$value = 'test';
+	}
+
+	if ($key === 1) {
+		echo $value;
+	}
+}
+
+function bar(): void {
+	$key = rand(0, 2);
+
+	if ($key === 2) {
+		$value = 'two';
+	}
+
+	if ($key === 1) {
+		$value = 'one';
+	}
+
+	if ($key === 2) {
+		echo $value;
+	}
+}
+
+function baz(): void {
+	$key = rand(0, 3);
+
+	if ($key === 1) {
+		$value = 'one';
+	}
+
+	if ($key === 2) {
+		$value = 'two';
+	}
+
+	if ($key === 3) {
+		echo $value; // SHOULD report "is not defined"
+	}
+}
+
+function boo(): void {
+	$key = rand(0, 2);
+
+	if ($key === 1) {
+		$value = 'test';
+	}
+
+	if ($key === 1) {
+		unset($value);
+	}
+
+	if ($key === 1) {
+		echo $value;
+	}
+}
+
+function loo(): void {
+	$key = rand(0, 2);
+
+	if ($key === 1) {
+		$value = 'test';
+	}
+
+	if ($key === 1 || $key === 2) {
+		unset($value);
+	}
+
+	if ($key === 1) {
+		echo $value;
+	}
+}
diff --git a/tests/PHPStan/Rules/Variables/data/bug-6830.php b/tests/PHPStan/Rules/Variables/data/bug-6830.php
new file mode 100644
index 0000000000..1a4e5a4490
--- /dev/null
+++ b/tests/PHPStan/Rules/Variables/data/bug-6830.php
@@ -0,0 +1,18 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Bug6830;
+
+/** @param array<bool> $bools */
+function test(array $bools): void
+{
+	foreach ($bools as $bool) {
+		if ($bool) {
+			$foo = 'foo';
+		}
+		if ($bool) {
+			echo $foo;
+		}
+	}
+}
diff --git a/tests/PHPStan/Rules/Variables/data/bug-8430.php b/tests/PHPStan/Rules/Variables/data/bug-8430.php
new file mode 100644
index 0000000000..9ec7e1c436
--- /dev/null
+++ b/tests/PHPStan/Rules/Variables/data/bug-8430.php
@@ -0,0 +1,31 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Bug8430;
+
+class B
+{
+	public function abc(string $a, bool $b): void
+	{
+		for ($i = 1; $i <= 5; $i++) {
+			if (!$b) {
+				$arr = ['a' => 1];
+			}
+			if (!$a && !$b) {
+				echo $arr['a'];
+			}
+		}
+	}
+
+	public function def(string $a, bool $b): void
+	{
+		if (!$b) {
+			$arr = ['a' => 1];
+		}
+		if (!$a && !$b) {
+			echo $arr['a'];
+		}
+	}
+}
+
diff --git a/tests/PHPStan/Rules/Variables/data/bug-8430b.php b/tests/PHPStan/Rules/Variables/data/bug-8430b.php
new file mode 100644
index 0000000000..4622031dd7
--- /dev/null
+++ b/tests/PHPStan/Rules/Variables/data/bug-8430b.php
@@ -0,0 +1,111 @@
+<?php
+
+declare(strict_types=1);
+
+namespace Bug8430b;
+
+class A
+{
+	/** @var A[][] */
+	public array $a;
+	/** @var A[] */
+	public array $b;
+	/** @var array<string,string|string[]> */
+	public array $c;
+	public string $d;
+}
+
+class B
+{
+	private function abc(): void
+	{
+	}
+
+	/**
+	 * @param A[] $a
+	 * @param array<string,string> $b
+	 */
+	public function def(array $a, array $b, string $c, bool $d): void
+	{
+		$e = false;
+		$f = false;
+		switch ($b['repeat'] ?? null) {
+			case 'Y':
+				$e = true;
+				break;
+			case 'A':
+				$e = true;
+				$f = true;
+				break;
+		}
+		$g = 5;
+		$h = 0;
+		for ($i = 1; $i <= $g; $i++) {
+			if (!$d) {
+				$arr = ['a' => 1];
+			}
+			$j = $a[$i] ?? null;
+			if ($j) {
+				/** @var array<A[]> $k */
+				$k = [];
+				if ($e) {
+					foreach ($j->a as $l) {
+						/** @var A[] $m */
+						$m = $f || empty($k) ? $j->b : [];
+						array_push($m, ...$l);
+						array_push($k, $m);
+					}
+					if (empty($k)) {
+						array_push($k, $j->b);
+					}
+				} else {
+					array_push($k, $j->b);
+					foreach ($j->a as $l) {
+						array_push($k[0], ...$l);
+						break;
+					}
+				}
+				foreach ($k as $n) {
+					if (!$d) {
+						foreach ($n as $o) {
+							switch ($o->c['x'] ?? '') {
+								case 'y':
+									$p = $o->c[$o->d] ?? null;
+									if (is_array($p)) {
+										$this->abc();
+									}
+									break;
+								case 'z':
+									$p = $o->c[$o->d] ?? null;
+									if (is_array($p)) {
+										$this->abc();
+									}
+									break;
+								default:
+									$this->abc();
+									break;
+							}
+						}
+					}
+					if (!empty($n)) {
+						$h++;
+					}
+				}
+			}
+			if (!$c && !$d) {
+				echo $arr['a'];
+			}
+		}
+	}
+
+	public function ghi(string $a, bool $b): void
+	{
+		if (!$b) {
+			$arr = ['a' => 1];
+		}
+		$this->abc();
+		if (!$a && !$b) {
+			echo $arr['a'];
+		}
+	}
+}