diff --git a/modules/juce_core/streams/juce_MemoryOutputStream.cpp b/modules/juce_core/streams/juce_MemoryOutputStream.cpp
index 835b2bd793..adbaed2f2b 100644
--- a/modules/juce_core/streams/juce_MemoryOutputStream.cpp
+++ b/modules/juce_core/streams/juce_MemoryOutputStream.cpp
@@ -182,7 +182,7 @@ int64 MemoryOutputStream::writeFromInputStream (InputStream& source, int64 maxNu
 
     if (availableData > 0)
     {
-        if (maxNumBytesToWrite > availableData)
+        if (maxNumBytesToWrite > availableData || maxNumBytesToWrite < 0)
             maxNumBytesToWrite = availableData;
 
         if (blockToUse != nullptr)