diff --git a/examples/model_coupling/runtests.jl b/examples/model_coupling/runtests.jl
index f3d32489..81d09924 100644
--- a/examples/model_coupling/runtests.jl
+++ b/examples/model_coupling/runtests.jl
@@ -54,7 +54,7 @@ Mads.madsinfo("External coupling using `Command` and JSON ...")
 md = Mads.loadmadsfile(joinpath(workdir, "external-json-exp.mads"))
 # sparam, sresults = Mads.calibrate(md)
 efor = Mads.forward(md)
-if !haskey(ENV, "MADS_NO_PYTHON")
+if !haskey(ENV, "MADS_NO_PYTHON") && isdefined(Mads, :yaml)
 	Mads.madsinfo("External coupling using `Command` and YAML ...")
 	md = Mads.loadmadsfile(joinpath(workdir, "external-yaml.mads"))
 	# yparam, yresults = Mads.calibrate(md)
diff --git a/examples/optimization/runtests.jl b/examples/optimization/runtests.jl
index d7126493..81a61e59 100644
--- a/examples/optimization/runtests.jl
+++ b/examples/optimization/runtests.jl
@@ -12,7 +12,7 @@ if Mads.long_tests
 	md = Mads.loadmadsfile(joinpath(workdir, "external-jld.mads"))
 	jparam, jresults = Mads.calibrate(md, maxEval=2, np_lambda=1, maxJacobians=1)
 
-	if !haskey(ENV, "MADS_NO_PYTHON")
+	if !haskey(ENV, "MADS_NO_PYTHON") && isdefined(Mads, :yaml)
 		md = Mads.loadmadsfile(joinpath(workdir, "external-yaml.mads"))
 		yparam, yresults = Mads.calibrate(md, maxEval=2, np_lambda=1, maxJacobians=1)
 		@Base.Test.test yparam == jparam