diff --git a/packages/babel-helper-explode-assignable-expression/src/index.js b/packages/babel-helper-explode-assignable-expression/src/index.js
index c854e1c382..8ffdd95fa2 100644
--- a/packages/babel-helper-explode-assignable-expression/src/index.js
+++ b/packages/babel-helper-explode-assignable-expression/src/index.js
@@ -41,7 +41,7 @@ function getObjRef(node, nodes, file, scope) {
 function getPropRef(node, nodes, file, scope) {
   let prop = node.property;
   let key = t.toComputedKey(node, prop);
-  if (t.isLiteral(key)) return key;
+  if (t.isLiteral(key) && t.isPureish(key)) return key;
 
   let temp = scope.generateUidIdentifierBasedOnNode(prop);
   nodes.push(t.variableDeclaration("var", [
diff --git a/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/regression/4403/actual.js b/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/regression/4403/actual.js
new file mode 100644
index 0000000000..62ddaa92b9
--- /dev/null
+++ b/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/regression/4403/actual.js
@@ -0,0 +1,2 @@
+var a, b;
+a[`${b++}`] **= 1;
diff --git a/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/regression/4403/expected.js b/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/regression/4403/expected.js
new file mode 100644
index 0000000000..dbf2e9bdb1
--- /dev/null
+++ b/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/regression/4403/expected.js
@@ -0,0 +1,3 @@
+var a, b;
+var _ref = `${ b++ }`;
+a[_ref] = Math.pow(a[_ref], 1)
diff --git a/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/regression/4403/options.json b/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/regression/4403/options.json
new file mode 100644
index 0000000000..a6b3a4360b
--- /dev/null
+++ b/packages/babel-plugin-transform-exponentiation-operator/test/fixtures/regression/4403/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": ["transform-exponentiation-operator"]
+}