diff --git a/modules/juce_core/native/juce_posix_SharedCode.h b/modules/juce_core/native/juce_posix_SharedCode.h
index 831a25cca5..ac7c1990af 100644
--- a/modules/juce_core/native/juce_posix_SharedCode.h
+++ b/modules/juce_core/native/juce_posix_SharedCode.h
@@ -578,6 +578,7 @@ void MemoryMappedFile::openInternal (const File& file, AccessMode mode, bool exc
         }
 
         close (fileHandle);
+        fileHandle = 0;
     }
 }