diff --git a/legacy/src/Command/Organization/OrganizationCommandBase.php b/legacy/src/Command/Organization/OrganizationCommandBase.php
index e07317de8..275eefaf6 100644
--- a/legacy/src/Command/Organization/OrganizationCommandBase.php
+++ b/legacy/src/Command/Organization/OrganizationCommandBase.php
@@ -117,7 +117,10 @@ protected function chooseMember(Organization $organization): Member
             }
             $userId = $this->questionHelper->choose($choices, 'Enter a number to choose a user:', $default);
         } else {
-            $userId = $this->questionHelper->askInput('Enter an email address to choose a user', null, array_values($emailAddresses), function (string $email) use ($emailAddresses): string {
+            $userId = $this->questionHelper->askInput('Enter an email address to choose a user', null, array_values($emailAddresses), function (?string $email) use ($emailAddresses): string {
+                if ($email === null) {
+                    throw new InvalidArgumentException('An email address is required');
+                }
                 if (($key = array_search($email, $emailAddresses)) === false) {
                     throw new InvalidArgumentException('User not found: ' . $email);
                 }
diff --git a/legacy/src/Command/Organization/User/OrganizationUserAddCommand.php b/legacy/src/Command/Organization/User/OrganizationUserAddCommand.php
index 9098a13e9..262f0a107 100644
--- a/legacy/src/Command/Organization/User/OrganizationUserAddCommand.php
+++ b/legacy/src/Command/Organization/User/OrganizationUserAddCommand.php
@@ -81,7 +81,10 @@ protected function execute(InputInterface $input, OutputInterface $output): int
             } else {
                 $questionText = 'Optionally, enter a list of permissions to add (separated by commas)';
             }
-            $response = $this->questionHelper->askInput($questionText, null, [], function ($value) {
+            $response = $this->questionHelper->askInput($questionText, null, [], function (?string $value): ?string {
+                if ($value === null) {
+                    return null;
+                }
                 foreach (ArrayArgument::split([$value]) as $permission) {
                     if (!\in_array($permission, self::$allPermissions)) {
                         throw new InvalidArgumentException('Unrecognized permission: ' . $permission);
@@ -89,7 +92,7 @@ protected function execute(InputInterface $input, OutputInterface $output): int
                 }
                 return $value;
             });
-            $permissions = ArrayArgument::split([$response]);
+            $permissions = $response === null ? [] : ArrayArgument::split([$response]);
             $this->stdErr->writeln('');
         }
 
diff --git a/legacy/src/Command/Team/User/TeamUserAddCommand.php b/legacy/src/Command/Team/User/TeamUserAddCommand.php
index b205879c3..1c65f54e7 100644
--- a/legacy/src/Command/Team/User/TeamUserAddCommand.php
+++ b/legacy/src/Command/Team/User/TeamUserAddCommand.php
@@ -56,9 +56,12 @@ protected function execute(InputInterface $input, OutputInterface $output): int
                     $emails[] = $info->email;
                 }
             }
-            $identifier = $this->questionHelper->askInput('Enter an email address to add a user', null, $emails, function (string $value): string {
+            $identifier = $this->questionHelper->askInput('Enter an email address to add a user', null, $emails, function (?string $value): string {
+                if ($value === null) {
+                    throw new InvalidArgumentException('An email address is required');
+                }
                 if (!filter_var($value, FILTER_VALIDATE_EMAIL)) {
-                    throw new InvalidArgumentException('Invalid email address:' . $value);
+                    throw new InvalidArgumentException('Invalid email address: ' . $value);
                 }
                 return $value;
             });
diff --git a/legacy/src/Selector/Selector.php b/legacy/src/Selector/Selector.php
index 1daa00f82..b8dbe834f 100644
--- a/legacy/src/Selector/Selector.php
+++ b/legacy/src/Selector/Selector.php
@@ -453,8 +453,8 @@ private function offerProjectChoice(array $projectInfos, SelectorConfig $config)
                 }
             }
             asort($autocomplete, SORT_NATURAL | SORT_FLAG_CASE);
-            return $this->questionHelper->askInput($config->enterProjectText, null, array_values($autocomplete), function ($value) use ($autocomplete): string {
-                [$id, ] = explode(' - ', $value);
+            return $this->questionHelper->askInput($config->enterProjectText, null, array_values($autocomplete), function (?string $value) use ($autocomplete): string {
+                [$id] = explode(' - ', $value ?? '', 2);
                 if (empty(trim($id))) {
                     throw new InvalidArgumentException('A project ID is required');
                 }
@@ -495,7 +495,10 @@ private function offerEnvironmentChoice(InputInterface $input, Project $project,
             $ids = array_keys($environments);
             sort($ids, SORT_NATURAL | SORT_FLAG_CASE);
 
-            $id = $this->questionHelper->askInput($config->enterEnvText, $defaultEnvironmentId, array_keys($environments), function (string $value) use ($environments): string {
+            $id = $this->questionHelper->askInput($config->enterEnvText, $defaultEnvironmentId, array_keys($environments), function (?string $value) use ($environments): string {
+                if ($value === null || $value === '') {
+                    throw new \RuntimeException('An environment ID is required');
+                }
                 if (!isset($environments[$value])) {
                     throw new \RuntimeException('Environment not found: ' . $value);
                 }