diff --git a/src/building_blocks.jl b/src/building_blocks.jl
index 4271bd4a6a24391274c3c6d0e08431dc20d54061..f2219f475f79a154350151d8ddd3d564ac9a0d11 100644
--- a/src/building_blocks.jl
+++ b/src/building_blocks.jl
@@ -187,6 +187,7 @@ function _robust_value(possible_vector::AbstractVector)
     if any(isnothing.(result))
         return nothing
     end
+    return result
 end
 
 function Base.show(io::IO, printer::BuildingBlockPrinter)