diff --git a/src/main/kotlin/alfred/web/system/ProcessEnvironment.kt b/src/main/kotlin/alfred/web/system/ProcessEnvironment.kt
index 7de4ab4..9f61370 100644
--- a/src/main/kotlin/alfred/web/system/ProcessEnvironment.kt
+++ b/src/main/kotlin/alfred/web/system/ProcessEnvironment.kt
@@ -22,7 +22,7 @@ class ProcessEnvironment {
             val newEnv = mutableMapOf<String, String>()
             newEnv.putAll(env)
 
-            newEnv.filter { it.key.contains("ALFRED") }.forEach { env.remove(it.key) }
+            newEnv.filter { it.key.contains("ALFRED") }.forEach { newEnv.remove(it.key) }
             newEnv.putAll(config.env)
             newEnv["ALFRED_LOG_FILE"] = logFile.backingFile.absolutePath
             newEnv["ALFRED_REV"] = rev ?: ""