diff --git a/var/spack/repos/builtin/packages/petsc/package.py b/var/spack/repos/builtin/packages/petsc/package.py
index e801b4d2967..0a44765056d 100644
--- a/var/spack/repos/builtin/packages/petsc/package.py
+++ b/var/spack/repos/builtin/packages/petsc/package.py
@@ -159,6 +159,8 @@ class Petsc(Package):
 
     patch('xlf_fix-dup-petscfecreate.patch', when='@3.11.0')
 
+    depends_on('diffutils', type='build')
+
     # Virtual dependencies
     # Git repository needs sowing to build Fortran interface
     depends_on('sowing', when='@develop')