diff --git a/src/index.js b/src/index.js
index 8f95336..e9ff9d0 100644
--- a/src/index.js
+++ b/src/index.js
@@ -239,7 +239,7 @@ let customToStringHandlerToGuesstimateSyntax = (node, options) => {
   }
 };
 
-let toPrecision2 = (f) => f.toPrecision(2);
+let toPrecision2 = (f) => f.toPrecision(2).toString();
 let toShortGuesstimateString = (node) => {
   if (isArgLognormal(node)) {
     let factors = getFactors(node);