diff --git a/build_pop.py b/build_pop.py
index 7c6e70e3a42589431a6ae8570620bd944a9b0161..79d17efbcc136dd42b478a1f0bb70d93010eb6f3 100755
--- a/build_pop.py
+++ b/build_pop.py
@@ -380,7 +380,7 @@ def init(output_dir, force_outputdir, sv_list, nstretches, nb_inds, reference, p
         print("")
     except InputException as e:
         eprint(e)
-        return False
+        return -1
     if quiet or confirm(deletions, sv_sim.variants):
         genotypes_for_inds = build_genotypes_vcf_list(deletions, output_vcf, haploid, force_polymorphism, nb_inds,
                                                       tmp_dir, prg_path)
@@ -390,6 +390,7 @@ def init(output_dir, force_outputdir, sv_list, nstretches, nb_inds, reference, p
         print("DONE!\n")
     else:
         print("Aborted!\n")
+    return 0
 
 
 def main():