diff --git a/src/link/output.c b/src/link/output.c
index 805d0bb1..d7bd7132 100644
--- a/src/link/output.c
+++ b/src/link/output.c
@@ -111,6 +111,11 @@ static void checkOverlay(void)
 					nbOverlayBanks);
 		if (!sections[SECTTYPE_ROMX].banks)
 			err(1, "Failed to realloc banks for overlay");
+		for (uint32_t i = sections[SECTTYPE_ROMX].nbBanks;
+		     i < nbOverlayBanks; i++) {
+			sections[SECTTYPE_ROMX].banks[i].sections = NULL;
+			sections[SECTTYPE_ROMX].banks[i].zeroLenSections = NULL;
+		}
 		sections[SECTTYPE_ROMX].nbBanks = nbOverlayBanks;
 	}
 }