diff --git a/runtime/io-error.cpp b/runtime/io-error.cpp
index f73272a..9c4a5c7 100644
--- a/runtime/io-error.cpp
+++ b/runtime/io-error.cpp
@@ -23,7 +23,7 @@
       ioStat_ = IostatEnd;
     }
   } else if (iostatOrErrno == IostatEor && (flags_ & hasEor)) {
-    if (!ioStat_ == IostatOk || ioStat_ < IostatEor) {
+    if (ioStat_ == IostatOk || ioStat_ < IostatEor) {
       ioStat_ = IostatEor; // least priority
     }
   } else if (iostatOrErrno != IostatOk) {