diff --git a/src/Type/WebMozartAssert/AssertTypeSpecifyingExtension.php b/src/Type/WebMozartAssert/AssertTypeSpecifyingExtension.php
index 9b35420..ce490f7 100644
--- a/src/Type/WebMozartAssert/AssertTypeSpecifyingExtension.php
+++ b/src/Type/WebMozartAssert/AssertTypeSpecifyingExtension.php
@@ -754,18 +754,17 @@ private function getExpressionResolvers(): array
 						)
 					);
 				},
+				'contains' => static function (Scope $scope, Arg $value, Arg $subString): array {
+					return self::createContainsResolver($scope, $value, $subString);
+				},
+				'startsWith' => static function (Scope $scope, Arg $value, Arg $subString): array {
+					return self::createStartsWithResolver($scope, $value, $subString);
+				},
+				'endsWith' => static function (Scope $scope, Arg $value, Arg $subString): array {
+					return self::createEndsWithResolver($scope, $value, $subString);
+				},
 			];
 
-			foreach (['contains', 'startsWith', 'endsWith'] as $name) {
-				$this->resolvers[$name] = function (Scope $scope, Arg $value, Arg $subString) use ($name): array {
-					if ($scope->getType($subString->value)->isNonEmptyString()->yes()) {
-						return self::createIsNonEmptyStringAndSomethingExprPair($name, [$value, $subString]);
-					}
-
-					return [$this->resolvers['string']($scope, $value), null];
-				};
-			}
-
 			$assertionsResultingAtLeastInNonEmptyString = [
 				'startsWithLetter',
 				'unicodeLetters',
@@ -1022,4 +1021,138 @@ private function specifyRootExprIfSet(?Expr $rootExpr, SpecifiedTypes $specified
 		);
 	}
 
+	/**
+	 * @return array{Expr, Expr}
+	 */
+	private static function createContainsResolver(Scope $scope, Arg $value, Arg $subString): array
+	{
+		$stringExpr = $scope->getType($subString->value)->isNonEmptyString()->yes()
+			? new BooleanAnd(
+				new FuncCall(
+					new Name('is_string'),
+					[$value]
+				),
+				new NotIdentical(
+					$value->value,
+					new String_('')
+				)
+			)
+			: new FuncCall(
+				new Name('is_string'),
+				[$value]
+			);
+
+		$expr = new BooleanOr(
+			$stringExpr,
+			new BooleanAnd(
+				$stringExpr,
+				new GreaterOrEqual(
+					new FuncCall(
+						new Name('strpos'),
+						[$value]
+					),
+					new LNumber(0)
+				)
+			)
+		);
+
+		$rootExpr = new BooleanAnd(
+			$expr,
+			new FuncCall(new Name('FAUX_FUNCTION_ contains'), [$value, $subString])
+		);
+
+		return [$expr, $rootExpr];
+	}
+
+	/**
+	 * @return array{Expr, Expr}
+	 */
+	private static function createStartsWithResolver(Scope $scope, Arg $string, Arg $subString): array
+	{
+		$stringExpr = $scope->getType($subString->value)->isNonEmptyString()->yes()
+			? new BooleanAnd(
+				new FuncCall(
+					new Name('is_string'),
+					[$string]
+				),
+				new NotIdentical(
+					$string->value,
+					new String_('')
+				)
+			)
+			: new FuncCall(
+				new Name('is_string'),
+				[$string]
+			);
+
+		$expr = new BooleanOr(
+			$stringExpr,
+			new Identical(
+				new FuncCall(
+					new Name('strpos'),
+					[$string, $subString]
+				),
+				new LNumber(0)
+			)
+		);
+
+		$rootExpr = new BooleanAnd(
+			$expr,
+			new FuncCall(new Name('FAUX_FUNCTION_ startsWith'), [$string, $subString])
+		);
+
+		return [$expr, $rootExpr];
+	}
+
+	/**
+	 * @return array{Expr, Expr}
+	 */
+	private static function createEndsWithResolver(Scope $scope, Arg $value, Arg $subString): array
+	{
+		if ($scope->getType($subString->value)->isNonEmptyString()->yes()) {
+			$stringExpr = new BooleanAnd(
+				new FuncCall(
+					new Name('is_string'),
+					[$value]
+				),
+				new NotIdentical(
+					$value->value,
+					new String_('')
+				)
+			);
+		} else {
+			$stringExpr = new FuncCall(
+				new Name('is_string'),
+				[$value]
+			);
+		}
+
+		$expr = new BooleanOr(
+			$stringExpr,
+			new Identical(
+				new FuncCall(
+					new Name('strpos'),
+					[$value, $subString]
+				),
+				new BinaryOp\Minus(
+					new FuncCall(
+						new Name('strlen'),
+						[$value]
+					),
+					new FuncCall(
+						new Name('strlen'),
+						[$subString]
+					)
+				)
+			)
+		);
+
+		$rootExpr = new BooleanAnd(
+			$expr,
+			new FuncCall(new Name('FAUX_FUNCTION_ endsWith'), [$value, $subString])
+		);
+
+		return [$expr, $rootExpr];
+	}
+
 }
diff --git a/tests/Type/WebMozartAssert/ImpossibleCheckTypeMethodCallRuleTest.php b/tests/Type/WebMozartAssert/ImpossibleCheckTypeMethodCallRuleTest.php
index 95b1dfc..aa860de 100644
--- a/tests/Type/WebMozartAssert/ImpossibleCheckTypeMethodCallRuleTest.php
+++ b/tests/Type/WebMozartAssert/ImpossibleCheckTypeMethodCallRuleTest.php
@@ -105,6 +105,10 @@ public function testExtension(): void
 				'Call to static method Webmozart\Assert\Assert::isInstanceOf() with Exception and class-string<Exception> will always evaluate to true.',
 				119,
 			],
+			[
+				'Call to static method Webmozart\Assert\Assert::startsWith() with \'value\' and string will always evaluate to true.',
+				126,
+			],
 		]);
 	}
 
diff --git a/tests/Type/WebMozartAssert/data/impossible-check.php b/tests/Type/WebMozartAssert/data/impossible-check.php
index 271efc3..0e00dcc 100644
--- a/tests/Type/WebMozartAssert/data/impossible-check.php
+++ b/tests/Type/WebMozartAssert/data/impossible-check.php
@@ -119,6 +119,14 @@ public function testInstanceOfClassString(\Exception $e, string $name): void
 		Assert::isInstanceOf($e, $name);
 	}
 
+	public function testStartsWith(string $a): void
+	{
+		Assert::startsWith("value", "val");
+		Assert::startsWith("value", $a);
+		Assert::startsWith("value", $a);
+		Assert::startsWith("value", "bix");
+	}
+
 }
 
 interface Bar {};
diff --git a/tests/Type/WebMozartAssert/data/string.php b/tests/Type/WebMozartAssert/data/string.php
index 7ad6007..48ce019 100644
--- a/tests/Type/WebMozartAssert/data/string.php
+++ b/tests/Type/WebMozartAssert/data/string.php
@@ -29,7 +29,7 @@ public function startsWith(string $a, string $b): void
 		assertType('string', $a);
 
 		Assert::startsWith($a, $b);
-		assertType('non-empty-string', $a);
+		assertType('string', $a);
 	}
 
 	public function startsWithLetter(string $a): void
@@ -47,7 +47,7 @@ public function endsWith(string $a, string $b): void
 		assertType('string', $a);
 
 		Assert::endsWith($a, $b);
-		assertType('non-empty-string', $a);
+		assertType('string', $a);
 	}
 
 	public function unicodeLetters($a): void