IRAC 3.6 μm image (17″ × 17″) centered on the position of the ALMA detection. We show the image before (left panel) and after (right panel) the subtraction with GALFIT of the bright source ID_ZFOURGE = 11024 (ID_CANDELS = 8067) located to the northeast of the detection and which masks the emission of the source located at the ALMA position. After subtraction we can clearly see emission located in the central position which suggests that the source is not present in Ashby et al. (2015) only because of blending. Green double crosses show sources only from the GOODS–South CANDELS catalog and white circles show sources only from the ZFOURGE catalog. Blue circles show common sources to both optical catalogs (i.e., sources with an angular separation lower than 04).