diff --git a/src/plugins/tests.jl b/src/plugins/tests.jl
index 596c623e..2e191622 100644
--- a/src/plugins/tests.jl
+++ b/src/plugins/tests.jl
@@ -127,6 +127,8 @@ function add_test_dependency(p::Tests, pkg_dir::AbstractString)
     # Add the dependency manually since there's no programmatic way to add to [extras].
     path = joinpath(pkg_dir, "Project.toml")
     toml = TOML.parsefile(path)
+
+    get!(toml, "compat", Dict())["Test"] = "1"
     
     get!(toml, "extras", Dict())["Test"] = TEST_UUID
     if p.aqua
diff --git a/test/fixtures/AllPlugins/Project.toml b/test/fixtures/AllPlugins/Project.toml
index 864d4292..050333d3 100644
--- a/test/fixtures/AllPlugins/Project.toml
+++ b/test/fixtures/AllPlugins/Project.toml
@@ -4,6 +4,7 @@ authors = ["tester"]
 version = "1.0.0-DEV"
 
 [compat]
+Test = "1"
 julia = "1.6.7"
 
 [extras]
diff --git a/test/fixtures/Basic/Project.toml b/test/fixtures/Basic/Project.toml
index b36eb6b5..f1efc6d8 100644
--- a/test/fixtures/Basic/Project.toml
+++ b/test/fixtures/Basic/Project.toml
@@ -4,6 +4,7 @@ authors = ["tester"]
 version = "1.0.0-DEV"
 
 [compat]
+Test = "1"
 julia = "1.6.7"
 
 [extras]
diff --git a/test/fixtures/DocumenterGitHubActions/Project.toml b/test/fixtures/DocumenterGitHubActions/Project.toml
index d8d1159b..0a28c8b4 100644
--- a/test/fixtures/DocumenterGitHubActions/Project.toml
+++ b/test/fixtures/DocumenterGitHubActions/Project.toml
@@ -4,6 +4,7 @@ authors = ["tester"]
 version = "1.0.0-DEV"
 
 [compat]
+Test = "1"
 julia = "1.6.7"
 
 [extras]
diff --git a/test/fixtures/DocumenterGitLabCI/Project.toml b/test/fixtures/DocumenterGitLabCI/Project.toml
index 7d9fd326..073ba821 100644
--- a/test/fixtures/DocumenterGitLabCI/Project.toml
+++ b/test/fixtures/DocumenterGitLabCI/Project.toml
@@ -4,6 +4,7 @@ authors = ["tester"]
 version = "1.0.0-DEV"
 
 [compat]
+Test = "1"
 julia = "1.6.7"
 
 [extras]
diff --git a/test/fixtures/DocumenterTravis/Project.toml b/test/fixtures/DocumenterTravis/Project.toml
index f4576731..c1a257ab 100644
--- a/test/fixtures/DocumenterTravis/Project.toml
+++ b/test/fixtures/DocumenterTravis/Project.toml
@@ -4,6 +4,7 @@ authors = ["tester"]
 version = "1.0.0-DEV"
 
 [compat]
+Test = "1"
 julia = "1.6.7"
 
 [extras]