diff --git a/agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/configuration/ConfigurationBuilder.java b/agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/configuration/ConfigurationBuilder.java
index 7146df15b5..fdc51eb24b 100644
--- a/agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/configuration/ConfigurationBuilder.java
+++ b/agent/agent-tooling/src/main/java/com/microsoft/applicationinsights/agent/internal/configuration/ConfigurationBuilder.java
@@ -743,7 +743,8 @@ static void overlayFromEnv(
     String replacedConnectionString = stringSubstitutor.replace(config.connectionString);
     if (replacedConnectionString != null
         && !replacedConnectionString.startsWith("InstrumentationKey=")
-        && config.connectionString.equals(replacedConnectionString)) {
+        && config.connectionString.equals(replacedConnectionString)
+        && System.getenv(APPLICATIONINSIGHTS_CONNECTION_STRING_ENV) == null) {
       throw new FriendlyException(
           "Your connection string seems to have a wrong format: \""
               + config.connectionString