diff --git a/test/Project.toml b/test/Project.toml
index bec7ba1..a4e3702 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -1,6 +1,6 @@
 [deps]
 Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
-GLPK = "60bf3e95-4087-53dc-ae20-288a0d20c6a6"
+Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
 HiGHS = "87dc4568-4c63-4d18-b0c0-bb2238e4078b"
 HydroPowerSimulations = "fc1677e0-6ad7-4515-bf3a-bd6bf20a0b1b"
 InfrastructureSystems = "2cd47ed4-ca9b-11e9-27f2-ab636a7671f1"
diff --git a/test/runtests.jl b/test/runtests.jl
index a224224..b2059e8 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -8,7 +8,6 @@ using PowerSimulations
 using PowerSystems
 using JuMP
 using HiGHS
-using GLPK
 using Dates
 
 const IS = InfrastructureSystems
@@ -44,9 +43,6 @@ HiGHS_optimizer = JuMP.optimizer_with_attributes(
     "log_to_console" => false,
 )
 
-GLPK_optimizer =
-    JuMP.optimizer_with_attributes(GLPK.Optimizer, "msg_lev" => GLPK.GLP_MSG_OFF)
-
 """
 Copied @includetests from https://github.com/ssfrr/TestSetExtensions.jl.
 Ideally, we could import and use TestSetExtensions.  Its functionality was broken by changes
diff --git a/test/test_storage_simulation.jl b/test/test_storage_simulation.jl
index 7c7b6a4..8e1941b 100644
--- a/test/test_storage_simulation.jl
+++ b/test/test_storage_simulation.jl
@@ -136,14 +136,14 @@ end
                 template_uc,
                 sys_uc;
                 name="UC",
-                optimizer=GLPK_optimizer,
+                optimizer=HiGHS_optimizer,
                 store_variable_names=true,
             ),
             DecisionModel(
                 template_ed,
                 sys_ed;
                 name="ED",
-                optimizer=GLPK_optimizer,
+                optimizer=HiGHS_optimizer,
                 store_variable_names=true,
             ),
         ],
diff --git a/test/test_utils/mock_operation_models.jl b/test/test_utils/mock_operation_models.jl
index e62feac..08903a6 100644
--- a/test/test_utils/mock_operation_models.jl
+++ b/test/test_utils/mock_operation_models.jl
@@ -185,8 +185,8 @@ function create_simulation_build_test_problems(
 )
     return SimulationModels(;
         decision_models=[
-            DecisionModel(template_uc, sys_uc; name="UC", optimizer=GLPK_optimizer),
-            DecisionModel(template_ed, sys_ed; name="ED", optimizer=GLPK_optimizer),
+            DecisionModel(template_uc, sys_uc; name="UC", optimizer=HiGHS_optimizer),
+            DecisionModel(template_ed, sys_ed; name="ED", optimizer=HiGHS_optimizer),
         ],
     )
 end