diff --git a/tests/aiger/generate_mk.py b/tests/aiger/generate_mk.py
index a90a63527..e6f3f4091 100644
--- a/tests/aiger/generate_mk.py
+++ b/tests/aiger/generate_mk.py
@@ -54,6 +54,13 @@ def create_tests():
         "rm -f aigmap.err"
     ]))
 
-extra = [ f"ABC ?= {gen_tests_makefile.yosys_basedir}/yosys-abc", "SHELL := /usr/bin/env bash" ]
+extra = [
+    "ifneq ($(ABCEXTERNAL),)",
+    "ABC ?= $(ABCEXTERNAL)",
+    "else",
+    f"ABC ?= {gen_tests_makefile.yosys_basedir}/yosys-abc",
+    "endif",
+    "SHELL := /usr/bin/env bash",
+]
 
 gen_tests_makefile.generate_custom(create_tests, extra)