diff --git a/packages/builder/src/builderStore/dataBinding.js b/packages/builder/src/builderStore/dataBinding.js
index 76a5717b9d..3e469fbe2e 100644
--- a/packages/builder/src/builderStore/dataBinding.js
+++ b/packages/builder/src/builderStore/dataBinding.js
@@ -171,51 +171,46 @@ export const getSchemaForDatasource = datasource => {
 }
 
 /**
- * Converts a readable data binding into a runtime data binding
+ * utility function for the readableToRuntimeBinding and runtimeToReadableBinding.
  */
-export function readableToRuntimeBinding(bindableProperties, textWithBindings) {
+function bindingReplacement(bindableProperties, textWithBindings, convertTo) {
+  const convertFrom = convertTo === "runtimeBinding" ? "readableBinding" : "runtimeBinding"
   if (typeof textWithBindings !== "string") {
     return textWithBindings
   }
+  const convertFromProps = bindableProperties
+    .map(el => el[convertFrom])
+    .sort((a, b) => {
+      return b.length - a.length
+    })
   const boundValues = textWithBindings.match(CAPTURE_VAR_INSIDE_TEMPLATE) || []
   let result = textWithBindings
   for (let boundValue of boundValues) {
-    const binding = bindableProperties.find(({ readableBinding }) => {
-      return boundValue.includes(readableBinding)
-    })
-    let newBoundValue = INVALID_BINDING
-    if (binding) {
-      newBoundValue = boundValue.replace(
-        binding.readableBinding,
-        binding.runtimeBinding
-      )
+    let newBoundValue = boundValue
+    for (let from of convertFromProps) {
+      if (newBoundValue.includes(from)) {
+        const binding = bindableProperties.find(el => el[convertFrom] === from)
+        newBoundValue = newBoundValue.replace(
+          from,
+          binding[convertTo],
+        )
+      }
     }
     result = result.replace(boundValue, newBoundValue)
   }
   return result
 }
 
+/**
+ * Converts a readable data binding into a runtime data binding
+ */
+export function readableToRuntimeBinding(bindableProperties, textWithBindings) {
+  return bindingReplacement(bindableProperties, textWithBindings, "runtimeBinding")
+}
+
 /**
  * Converts a runtime data binding into a readable data binding
  */
 export function runtimeToReadableBinding(bindableProperties, textWithBindings) {
-  if (typeof textWithBindings !== "string") {
-    return textWithBindings
-  }
-  const boundValues = textWithBindings.match(CAPTURE_VAR_INSIDE_TEMPLATE) || []
-  let result = textWithBindings
-  for (let boundValue of boundValues) {
-    const binding = bindableProperties.find(({ runtimeBinding }) => {
-      return boundValue.includes(runtimeBinding)
-    })
-    let newBoundValue = INVALID_BINDING
-    if (binding) {
-      newBoundValue = boundValue.replace(
-        binding.runtimeBinding,
-        binding.readableBinding
-      )
-    }
-    result = result.replace(boundValue, newBoundValue)
-  }
-  return result
+  return bindingReplacement(bindableProperties, textWithBindings, "readableBinding")
 }
diff --git a/packages/string-templates/rollup.config.js b/packages/string-templates/rollup.config.js
index 5a71316fb5..59d2f6acdc 100644
--- a/packages/string-templates/rollup.config.js
+++ b/packages/string-templates/rollup.config.js
@@ -17,6 +17,7 @@ export default {
   ],
   plugins: [
     resolve({
+      mainFields: ["module", "main"],
       preferBuiltins: true,
       browser: true,
     }),
diff --git a/packages/string-templates/src/index.js b/packages/string-templates/src/index.js
index 8318454b0b..8c99990ad7 100644
--- a/packages/string-templates/src/index.js
+++ b/packages/string-templates/src/index.js
@@ -116,7 +116,9 @@ module.exports.isValid = string => {
     hbsInstance.compile(processors.preprocess(string, false))(context)
     return true
   } catch (err) {
-    return false
+    // special case for maths functions - don't have inputs yet
+    return !!(err && err.message.includes("isNumber"))
+
   }
 }
 
diff --git a/packages/string-templates/test/helpers.spec.js b/packages/string-templates/test/helpers.spec.js
index dcddd8b9e6..7dbb36fa40 100644
--- a/packages/string-templates/test/helpers.spec.js
+++ b/packages/string-templates/test/helpers.spec.js
@@ -1,5 +1,6 @@
 const {
   processString,
+  isValid,
 } = require("../src/index")
 
 describe("test the custom helpers we have applied", () => {
@@ -289,4 +290,10 @@ describe("Cover a few complex use cases", () => {
     })
     expect(output).toBe("e")
   })
+
+  it("should make sure case is valid", () => {
+    const validity = isValid("{{ avg [c355ec2b422e54f988ae553c8acd811ea].[a] [c355ec2b422e54f988ae553c8acd811ea].[b] }}")
+
+    expect(validity).toBe(true)
+  })
 })
\ No newline at end of file