diff --git a/pkgs/servers/monitoring/prometheus/default.nix b/pkgs/servers/monitoring/prometheus/default.nix
index 62cb43abefaf..4b79103d7d50 100644
--- a/pkgs/servers/monitoring/prometheus/default.nix
+++ b/pkgs/servers/monitoring/prometheus/default.nix
@@ -55,6 +55,7 @@ buildGoModule rec {
 
     # Enable only select service discovery to shrink binaries.
     (
+      true  # prevent bash syntax error when all plugins are disabled
     ${lib.optionalString (enableAWS)
       "echo - github.com/prometheus/prometheus/discovery/aws"}
     ${lib.optionalString (enableAzure)