diff --git a/src/objective-c/GRPCClient/GRPCCall+Tests.m b/src/objective-c/GRPCClient/GRPCCall+Tests.m
index bade0b29208249f043cd58448a94203581f9aac8..c8e81337031a7b3c605c5cd6c7c94f83bc760306 100644
--- a/src/objective-c/GRPCClient/GRPCCall+Tests.m
+++ b/src/objective-c/GRPCClient/GRPCCall+Tests.m
@@ -40,6 +40,9 @@
 + (void)useTestCertsPath:(NSString *)certsPath
                 testName:(NSString *)testName
                  forHost:(NSString *)host {
+  if (!host || !certsPath || !testName) {
+    [NSException raise:NSInvalidArgumentException format:@"host, path and name must be provided."];
+  }
   GRPCHost *hostConfig = [GRPCHost hostWithAddress:host];
   hostConfig.pathToCertificates = certsPath;
   hostConfig.hostNameOverride = testName;