diff --git a/modules/juce_core/native/juce_mac_Files.mm b/modules/juce_core/native/juce_mac_Files.mm
index c5614e6ba5..564ccc7ec0 100644
--- a/modules/juce_core/native/juce_mac_Files.mm
+++ b/modules/juce_core/native/juce_mac_Files.mm
@@ -414,8 +414,10 @@ bool JUCE_CALLTYPE Process::openDocument (const String& fileName, const String&
         NSWorkspace* workspace = [NSWorkspace sharedWorkspace];
 
         if (parameters.isEmpty())
-            return [workspace openFile: juceStringToNS (fileName)]
-                || [workspace openURL: filenameAsURL];
+            // NB: the length check here is because of strange failures involving long filenames,
+            // probably due to filesystem name length limitations..
+            return (fileName.length() < 1024 && [workspace openFile: juceStringToNS (fileName)])
+                    || [workspace openURL: filenameAsURL];
 
         const File file (fileName);