diff --git a/checks.c b/checks.c
index 0524d41..4719d65 100644
--- a/checks.c
+++ b/checks.c
@@ -1580,10 +1580,14 @@ static void check_interrupts_property(struct check *c,
 		prop = get_property(parent, "interrupt-parent");
 		if (prop) {
 			phandle = propval_cell(prop);
-			/* Give up if this is an overlay with external references */
-			if ((phandle == 0 || phandle == -1) &&
-			    (dti->dtsflags & DTSF_PLUGIN))
+			if ((phandle == 0) || (phandle == -1)) {
+				/* Give up if this is an overlay with
+				 * external references */
+				if (dti->dtsflags & DTSF_PLUGIN)
 					return;
+				FAIL_PROP(c, dti, parent, prop, "Invalid phandle");
+				continue;
+			}
 
 			irq_node = get_node_by_phandle(root, phandle);
 			if (!irq_node) {