diff --git a/profile/WEB_CONCURRENCY.sh b/profile/WEB_CONCURRENCY.sh
index 50b1aeeb7..e5382cf49 100755
--- a/profile/WEB_CONCURRENCY.sh
+++ b/profile/WEB_CONCURRENCY.sh
@@ -58,7 +58,7 @@ appropriate for your application."
 DETECTED=$(detect_memory 512)
 export MEMORY_AVAILABLE=${MEMORY_AVAILABLE-$(bound_memory $DETECTED)}
 export WEB_MEMORY=${WEB_MEMORY-512}
-export WEB_CONCURRENCY=$(calculate_concurrency $MEMORY_AVAILABLE $WEB_MEMORY)
+export WEB_CONCURRENCY=${WEB_CONCURRENCY:-$(calculate_concurrency $MEMORY_AVAILABLE $WEB_MEMORY)}
 
 warn_bad_web_concurrency