diff --git a/flang/runtime/io-stmt.cpp b/flang/runtime/io-stmt.cpp
--- a/flang/runtime/io-stmt.cpp
+++ b/flang/runtime/io-stmt.cpp
@@ -315,6 +315,9 @@
   }
   if constexpr (DIR == Direction::Input) {
     BeginReadingRecord(); // in case there were no I/O items
+    if (mutableModes().nonAdvancing) {
+      unit().leftTabLimit = unit().furthestPositionInRecord;
+    }
     if (!mutableModes().nonAdvancing || GetIoStat() == IostatEor) {
       FinishReadingRecord();
     }
diff --git a/flang/runtime/unit.cpp b/flang/runtime/unit.cpp
--- a/flang/runtime/unit.cpp
+++ b/flang/runtime/unit.cpp
@@ -569,6 +569,9 @@
     if (IsAfterEndfile()) {
       // BACKSPACE after explicit ENDFILE
       currentRecordNumber = *endfileRecordNumber;
+    } else if (leftTabLimit) {
+      // BACKSPACE after non-advancing I/O
+      leftTabLimit.reset();
     } else {
       DoImpliedEndfile(handler);
       if (frameOffsetInFile_ + recordOffsetInFrame_ > 0) {