diff --git a/xwords4/common/memstream.c b/xwords4/common/memstream.c
index a6f07d04b..2413ed4eb 100644
--- a/xwords4/common/memstream.c
+++ b/xwords4/common/memstream.c
@@ -212,6 +212,20 @@ mem_stream_getBits( XWStreamCtxt* p_sctx, XP_U16 nBits )
     return result;
 } /* stream_getBits */
 
+static XP_U32
+mem_stream_getU32VL( XWStreamCtxt* p_sctx )
+{
+    XP_U32 result = 0;
+    for ( int ii = 0; ; ++ii ) {
+        XP_U8 byt = mem_stream_getBits( p_sctx, 8 * sizeof(byt) );
+        result |= (byt & 0x7F) << (7 * ii);
+        if ( 0 == (byt & 0x80) ) {
+            break;
+        }
+    }
+    return result;
+} /* mem_stream_getU32VL */
+
 #if defined DEBUG
 static void
 mem_stream_copyBits( const XWStreamCtxt* p_sctx, XWStreamPos endPos,
@@ -235,7 +249,6 @@ mem_stream_putBytes( XWStreamCtxt* p_sctx, const void* whence,
                      XP_U16 count )
 {
     MemStreamCtxt* stream = (MemStreamCtxt*)p_sctx;
-    XP_U32 newSize;
 
     if ( !stream->buf ) {
         XP_ASSERT( stream->nBytesAllocated == 0 );
@@ -255,7 +268,7 @@ mem_stream_putBytes( XWStreamCtxt* p_sctx, const void* whence,
        the new size is bigger than what we have, and if so expand to hold it
        plus something. */
 
-    newSize = stream->nBytesWritten + count;
+    XP_U32 newSize = stream->nBytesWritten + count;
     if ( stream->curWritePos < stream->nBytesWritten ) {
         newSize -= stream->nBytesWritten - stream->curWritePos;
     }
@@ -352,6 +365,25 @@ mem_stream_putBits( XWStreamCtxt* p_sctx, XP_U16 nBits, XP_U32 data
     XP_ASSERT( data == 0 );     /* otherwise nBits was too small */
 } /* mem_stream_putBits */
 
+/* Variable-length format: each 7 bits goes in a byte, with the 8th bit
+ * reserved for signaling whether there's another byte to come. */
+static void
+mem_stream_putU32VL( XWStreamCtxt* p_sctx, XP_U32 data )
+{
+    for ( ; ; ) {
+        XP_U8 byt = data & 0x7F;
+        data >>= 7;
+        XP_Bool haveMore = 0 != data;
+        if ( haveMore ) {
+            byt |= 0x80;
+        }
+        stream_putBits( p_sctx, 8 * sizeof(byt), byt );
+        if ( !haveMore ) {
+            break;
+        }
+    }
+} /* mem_stream_putU32VL */
+
 static void
 mem_stream_getFromStream( XWStreamCtxt* p_sctx, XWStreamCtxt* src, 
                           XP_U16 nBytes )
@@ -544,6 +576,7 @@ make_vtable( MemStreamCtxt* stream )
     SET_VTABLE_ENTRY( vtable, stream_getBytes, mem );
     SET_VTABLE_ENTRY( vtable, stream_getU16, mem );
     SET_VTABLE_ENTRY( vtable, stream_getU32, mem );
+    SET_VTABLE_ENTRY( vtable, stream_getU32VL, mem );
     SET_VTABLE_ENTRY( vtable, stream_getBits, mem );
 #if defined DEBUG
     SET_VTABLE_ENTRY( vtable, stream_copyBits, mem );
@@ -554,6 +587,7 @@ make_vtable( MemStreamCtxt* stream )
     SET_VTABLE_ENTRY( vtable, stream_catString, mem );
     SET_VTABLE_ENTRY( vtable, stream_putU16, mem );
     SET_VTABLE_ENTRY( vtable, stream_putU32, mem );
+    SET_VTABLE_ENTRY( vtable, stream_putU32VL, mem );
     SET_VTABLE_ENTRY( vtable, stream_putBits, mem );
 
     SET_VTABLE_ENTRY( vtable, stream_getFromStream, mem );
diff --git a/xwords4/common/xwstream.h b/xwords4/common/xwstream.h
index be86cb954..054e33561 100644
--- a/xwords4/common/xwstream.h
+++ b/xwords4/common/xwstream.h
@@ -65,6 +65,7 @@ typedef struct StreamCtxVTable {
                                XP_U16 count );
     XP_U16 (*m_stream_getU16)( DBG_PROC_FORMAL XWStreamCtxt* dctx );
     XP_U32 (*m_stream_getU32)( DBG_PROC_FORMAL XWStreamCtxt* dctx );
+    XP_U32 (*m_stream_getU32VL)( XWStreamCtxt* dctx );
     XP_U32 (*m_stream_getBits)( XWStreamCtxt* dctx, XP_U16 nBits );
 #if defined DEBUG
     void (*m_stream_copyBits)( const XWStreamCtxt* dctx, XWStreamPos endPos,
@@ -77,6 +78,7 @@ typedef struct StreamCtxVTable {
     void (*m_stream_catString)( XWStreamCtxt* dctx, const char* whence );
     void (*m_stream_putU16)( XWStreamCtxt* dctx, XP_U16 data );
     void (*m_stream_putU32)( XWStreamCtxt* dctx, XP_U32 data );
+    void (*m_stream_putU32VL)( XWStreamCtxt* dctx, XP_U32 data );
     void (*m_stream_putBits)( XWStreamCtxt* dctx, XP_U16 nBits, XP_U32 bits
                               DBG_LINE_FILE_FORMAL );
 
@@ -133,6 +135,9 @@ struct XWStreamCtxt {
 #define stream_getU32(sc) \
          (sc)->vtable->m_stream_getU32(DBG_PROC sc)
 
+#define stream_getU32VL(sc)                             \
+         (sc)->vtable->m_stream_getU32VL(sc)
+
 #define stream_getBits(sc, n) \
          (sc)->vtable->m_stream_getBits((sc), (n))
 
@@ -156,6 +161,9 @@ struct XWStreamCtxt {
 #define stream_putU32(sc, d) \
          (sc)->vtable->m_stream_putU32((sc), (d))
 
+#define stream_putU32VL(sc, d)                        \
+         (sc)->vtable->m_stream_putU32VL((sc), (d))
+
 #define stream_putBits(sc, n, b) \
          (sc)->vtable->m_stream_putBits((sc), (n), (b) DBG_LINE_FILE_PARM )
 
diff --git a/xwords4/linux/linuxmain.c b/xwords4/linux/linuxmain.c
index 9c175e461..d9009df7d 100644
--- a/xwords4/linux/linuxmain.c
+++ b/xwords4/linux/linuxmain.c
@@ -2561,6 +2561,36 @@ initParams( LaunchParams* params )
     params->dutil = linux_dutils_init( MPPARM(params->mpool) params->vtMgr, params );
 }
 
+static void
+testStreams( LaunchParams* params )
+{
+    XWStreamCtxt* stream = mem_stream_make_raw( MPPARM(params->dutil->mpool)
+                                                params->vtMgr );
+
+    XP_U32 nums[] = { 1, 4, 8, 200,
+                      makeRandomInt(),
+                      makeRandomInt(),
+                      makeRandomInt(),
+                      makeRandomInt(),
+                      makeRandomInt(),
+                      makeRandomInt(),
+    };
+
+    for ( int ii = 0; ii < VSIZE(nums); ++ii ) {
+        stream_putU32VL( stream, nums[ii] );
+        XP_LOGFF( "put num[%d]: %d", ii, nums[ii] );
+    }
+
+    for ( int ii = 0; ii < VSIZE(nums); ++ii ) {
+        XP_U32 num = stream_getU32VL( stream );
+        XP_LOGFF( "compariing num[%d]: %d with %d", ii, nums[ii], num );
+        XP_ASSERT( num == nums[ii] );
+    }
+
+    stream_destroy( stream, NULL );
+    XP_LOGFF( "OK!!" );
+}
+
 static void
 freeParams( LaunchParams* params )
 {
@@ -2672,6 +2702,7 @@ main( int argc, char** argv )
 #endif
 
     initParams( &mainParams );
+    testStreams( &mainParams );
 
     /* defaults */
     for ( int ii = 0; ii < VSIZE(mainParams.connInfo.inviteeCounts); ++ii ) {