diff --git a/nufxlib-0/Funnel.c b/nufxlib-0/Funnel.c
index 6032fae..2319346 100644
--- a/nufxlib-0/Funnel.c
+++ b/nufxlib-0/Funnel.c
@@ -172,12 +172,36 @@ Nu_ProgressDataExpandPrep(NuArchive* pArchive, NuFunnel* pFunnel,
     return kNuErrNone;
 }
 
+/*
+ * Compute a completion percentage.
+ */
+static int
+Nu_ComputePercent(ulong total, ulong progress)
+{
+    ulong perc;
+
+    if (!total)
+        return 0;
+
+    if (total < 21474836) {
+        perc = (progress * 100 + 50) / total;
+        if (perc > 100)
+            perc = 100;
+    } else {
+        perc = progress / (total / 100);
+        if (perc > 100)
+            perc = 100;
+    }
+
+    return (int) perc;
+}
+
 /*
  * Send the initial progress message, before the output file is opened
  * (when extracting) or the input file is opened (when adding).
  */
 NuError
-Nu_SendInitialProgress(NuArchive* pArchive, const NuProgressData* pProgress)
+Nu_SendInitialProgress(NuArchive* pArchive, NuProgressData* pProgress)
 {
     NuResult result;
 
@@ -187,6 +211,9 @@ Nu_SendInitialProgress(NuArchive* pArchive, const NuProgressData* pProgress)
     if (pProgress->progressFunc == nil)
         return kNuErrNone;
 
+    pProgress->percentComplete = Nu_ComputePercent(
+        pProgress->uncompressedLength, pProgress->uncompressedProgress);
+
     result = (*pProgress->progressFunc)(pArchive, (NuProgressData*) pProgress);
 
     if (result == kNuSkip)
@@ -703,7 +730,7 @@ Nu_StrawFree(NuArchive* pArchive, NuStraw* pStraw)
 
 
 /*
- * Set the Funnel's progress state.
+ * Set the Straw's progress state.
  */
 NuError
 Nu_StrawSetProgressState(NuStraw* pStraw, NuProgressState state)
diff --git a/nufxlib-0/NufxLibPriv.h b/nufxlib-0/NufxLibPriv.h
index 5125e60..a9bc467 100644
--- a/nufxlib-0/NufxLibPriv.h
+++ b/nufxlib-0/NufxLibPriv.h
@@ -615,8 +615,7 @@ NuError Nu_ProgressDataInit_Compress(NuArchive* pArchive,
 NuError Nu_ProgressDataInit_Expand(NuArchive* pArchive,
     NuProgressData* pProgressData, const NuRecord* pRecord,
     const char* newPathname, char newFssep, NuValue convertEOL);
-NuError Nu_SendInitialProgress(NuArchive* pArchive,
-    const NuProgressData* pProgress);
+NuError Nu_SendInitialProgress(NuArchive* pArchive, NuProgressData* pProgress);
 
 NuError Nu_FunnelNew(NuArchive* pArchive, NuDataSink* pDataSink,
     NuValue convertEOL, NuValue convertEOLTo, NuProgressData* pProgress,