diff --git a/pkgs/development/go-modules/generic/default.nix b/pkgs/development/go-modules/generic/default.nix
index 837f72a413db..b6af52d0efb8 100644
--- a/pkgs/development/go-modules/generic/default.nix
+++ b/pkgs/development/go-modules/generic/default.nix
@@ -106,7 +106,10 @@ let
       mkdir -p "''${GOPATH}/pkg/mod/cache/download"
       go mod download
     '' else ''
-      go mod vendor
+      if (( "''${NIX_DEBUG:-0}" >= 1 )); then
+        goModVendorFlags+=(-v)
+      fi
+      go mod vendor "''${goModVendorFlags[@]}"
     ''}
 
       mkdir -p vendor