diff --git a/YubiKit/YubiKit/Connections/NFCConnection/YKFNFCConnectionController.m b/YubiKit/YubiKit/Connections/NFCConnection/YKFNFCConnectionController.m
index 823ab9bd..e5a667d6 100644
--- a/YubiKit/YubiKit/Connections/NFCConnection/YKFNFCConnectionController.m
+++ b/YubiKit/YubiKit/Connections/NFCConnection/YKFNFCConnectionController.m
@@ -100,7 +100,9 @@ - (void)execute:(nonnull YKFAPDU *)command timeout:(NSTimeInterval)timeout compl
         }];
         
         // Lock the async call to enforce the sequential execution using the library dispatch queue.
-        dispatch_semaphore_wait(executionSemaphore, dispatch_time(DISPATCH_TIME_NOW, (int64_t)(timeout * NSEC_PER_SEC)));
+        if(dispatch_semaphore_wait(executionSemaphore, dispatch_time(DISPATCH_TIME_NOW, (int64_t)(timeout * NSEC_PER_SEC))) != 0) {
+            executionError = [YKFSessionError errorWithCode:YKFSessionErrorReadTimeoutCode];
+        }
         
         // Do not notify if the operation was canceled.
         if (operation.isCancelled) {
diff --git a/YubiKit/YubiKit/Connections/SmartCardConnection/YKFSmartCardConnectionController.m b/YubiKit/YubiKit/Connections/SmartCardConnection/YKFSmartCardConnectionController.m
index e2aed4cb..4ff43c91 100644
--- a/YubiKit/YubiKit/Connections/SmartCardConnection/YKFSmartCardConnectionController.m
+++ b/YubiKit/YubiKit/Connections/SmartCardConnection/YKFSmartCardConnectionController.m
@@ -131,7 +131,9 @@ - (void)execute:(nonnull YKFAPDU *)command timeout:(NSTimeInterval)timeout compl
         }];
         
         // Lock the async call to enforce the sequential execution using the library dispatch queue.
-        dispatch_semaphore_wait(executionSemaphore, dispatch_time(DISPATCH_TIME_NOW, (int64_t)(timeout * NSEC_PER_SEC)));
+        if(dispatch_semaphore_wait(executionSemaphore, dispatch_time(DISPATCH_TIME_NOW, (int64_t)(timeout * NSEC_PER_SEC))) != 0) {
+            executionError = [YKFSessionError errorWithCode:YKFSessionErrorReadTimeoutCode];
+        }
         
         // Do not notify if the operation was canceled.
         if (operation.isCancelled) {