diff --git a/easybuild/easyblocks/o/openfoam.py b/easybuild/easyblocks/o/openfoam.py
index 2cd60f364c..f7f56c4223 100644
--- a/easybuild/easyblocks/o/openfoam.py
+++ b/easybuild/easyblocks/o/openfoam.py
@@ -292,6 +292,24 @@ def configure_step(self):
                         env.setvar("BOOST_ROOT", get_software_root('Boost'))
                     else:
                         env.setvar("%s_ROOT" % depend.upper(), dependloc)
+            for dep in self.cfg.dependencies():
+                # CGAL >= 5.x is header-only, but when using it OpenFOAM still needs MPFR and GMP.
+                # It may fail to find them, so inject the right settings and paths into the "have_cgal" script.
+                if dep['name'] == 'CGAL' and LooseVersion(dep['version']) >= LooseVersion('5.0'):
+                    mpfr_root = get_software_root('MPFR')
+                    gmp_root = get_software_root('GMP')
+                    have_cgal_script = os.path.join(self.builddir, self.openfoamdir, 'wmake', 'scripts', 'have_cgal')
+                    eb_cgal_config = '''
+                    # Injected by EasyBuild
+                    HAVE_CGAL=true
+                    HAVE_MPFR=true
+                    CGAL_FLAVOUR=header
+                    CGAL_INC_DIR=${EBROOTCGAL}/include
+                    CGAL_LIB_DIR=${EBROOTCGAL}/lib
+                    MPFR_INC_DIR=${EBROOTMPFR}/include
+                    MPFR_LIB_DIR=${EBROOTMPFR}/lib
+                    '''
+                    apply_regex_substitutions(have_cgal_script, [(r"^(esac)$", r"\1\n" + eb_cgal_config)])
 
     def build_step(self):
         """Build OpenFOAM using make after sourcing script to set environment."""