diff --git a/src/constants.ts b/src/constants.ts
index 70cb7a46..1dee7aa0 100644
--- a/src/constants.ts
+++ b/src/constants.ts
@@ -15,5 +15,5 @@ export const STORYBLOK_AGENT = 'SB-Agent'
 export const STORYBLOK_JS_CLIENT_AGENT = {
 	defaultAgentName: 'SB-JS-CLIENT',
 	defaultAgentVersion: 'SB-Agent-Version',
-	packageVersion: process.env.npm_package_version || '5.0.0'
+	packageVersion: (typeof process !== 'undefined' && process.env.npm_package_version) || '5.0.0'
 }