diff --git a/modules/juce_core/javascript/juce_JSON.cpp b/modules/juce_core/javascript/juce_JSON.cpp
index eb939ad7f4..74f6bc8359 100644
--- a/modules/juce_core/javascript/juce_JSON.cpp
+++ b/modules/juce_core/javascript/juce_JSON.cpp
@@ -348,7 +348,12 @@ struct JSONFormatter
         }
         else if (v.isDouble())
         {
-            out << String (static_cast<double> (v), maximumDecimalPlaces);
+            auto d = static_cast<double> (v);
+
+            if (juce_isfinite (d))
+                out << String (d, maximumDecimalPlaces);
+            else
+                out << "null";
         }
         else if (v.isArray())
         {