diff --git a/nufxlib-0/Archive.c b/nufxlib-0/Archive.c
index c0c6f03..29eb27c 100644
--- a/nufxlib-0/Archive.c
+++ b/nufxlib-0/Archive.c
@@ -580,6 +580,24 @@ Nu_ReadMasterHeader(NuArchive* pArchive)
         }
     }
 
+    /*
+     * Check for an unusual condition.  GS/ShrinkIt appears to update
+     * the archive structure in the disk file periodically as it writes,
+     * so it's possible to get an apparently complete archive (with
+     * correct CRCs in the master and record headers!) that is actually
+     * only partially written.  I did this by accident when archiving a
+     * 3.5" disk across a slow AppleTalk network.  The only obvious
+     * indication of brain-damage, until you try to unpack the archive,
+     * seems to be a bogus MasterEOF==48.
+     */
+    if (pHeader->mhMasterEOF <= kNuMasterHeaderSize) {
+        err = kNuErrNoRecords;
+        Nu_ReportError(NU_BLOB, err,
+            "Master EOF is %ld, archive is probably truncated",
+            pHeader->mhMasterEOF);
+        goto bail;
+    }
+
     /*
      * Set up a few things in the archive structure on our way out.
      */
@@ -672,6 +690,7 @@ bail:
     if (err != kNuErrNone) {
         if (pArchive != nil)
             (void) Nu_NuArchiveFree(pArchive);
+        *ppArchive = nil;
     }
     return err;
 }
diff --git a/nufxlib-0/Lzw.c b/nufxlib-0/Lzw.c
index 437774c..aabce1c 100644
--- a/nufxlib-0/Lzw.c
+++ b/nufxlib-0/Lzw.c
@@ -1456,7 +1456,13 @@ Nu_ExpandLZW(NuArchive* pArchive, const NuRecord* pRecord,
             if (!isType2) {
                 err = Nu_ExpandLZW1(lzwState, rleLen);
             } else {
-                Assert(lzwState->dataInBuffer >= lzwLen);
+                if (lzwState->dataInBuffer < lzwLen) {
+                    /* rare -- GSHK will do this if you don't let it finish */
+                    err = kNuErrBufferUnderrun;
+                    Nu_ReportError(NU_BLOB, err, "not enough compressed data "
+                        "-- archive truncated during creation?");
+                    goto bail;
+                }
                 err = Nu_ExpandLZW2(lzwState, rleLen, lzwLen);
             }