diff --git a/AFNetworking/AFURLConnectionOperation.m b/AFNetworking/AFURLConnectionOperation.m
index 46a2d7b..5bc688c 100644
--- a/AFNetworking/AFURLConnectionOperation.m
+++ b/AFNetworking/AFURLConnectionOperation.m
@@ -623,7 +623,8 @@ willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challe
         switch (self.SSLPinningMode) {
             case AFSSLPinningModePublicKey: {
                 NSArray *pinnedPublicKeys = [self.class pinnedPublicKeys];
-                
+                NSAssert([pinnedPublicKeys count] > 0, @"AFSSLPinningModePublicKey needs at least one key file in the application bundle");
+
                 for (id publicKey in trustChain) {
                     for (id pinnedPublicKey in pinnedPublicKeys) {
                         if (AFSecKeyIsEqualToKey((__bridge SecKeyRef)publicKey, (__bridge SecKeyRef)pinnedPublicKey)) {
@@ -639,6 +640,7 @@ willSendRequestForAuthenticationChallenge:(NSURLAuthenticationChallenge *)challe
                 break;
             }
             case AFSSLPinningModeCertificate: {
+                NSAssert([[self.class pinnedCertificates] count] > 0, @"AFSSLPinningModeCertificate needs at least one certificate file in the application bundle");
                 for (id serverCertificateData in trustChain) {
                     if ([[self.class pinnedCertificates] containsObject:serverCertificateData]) {
                         NSURLCredential *credential = [NSURLCredential credentialForTrust:serverTrust];