diff --git a/apex/apex.go b/apex/apex.go
index fa796e5..bbcc4cc 100644
--- a/apex/apex.go
+++ b/apex/apex.go
@@ -1193,6 +1193,13 @@
 	}
 }
 
+type apexTransitionTag interface {
+	// ApexTransition is a temporary interface used to tag dependencies with the apex variation they should use
+	// when the dependency is added before the apex transition mutator has run.  These will be replaced with
+	// dependencies on the apex instead, which will then be used to find the necessary module inside the apex.
+	ApexTransition() string
+}
+
 type apexTransitionMutator struct{}
 
 func (a *apexTransitionMutator) Split(ctx android.BaseModuleContext) []string {
@@ -1207,6 +1214,9 @@
 }
 
 func (a *apexTransitionMutator) OutgoingTransition(ctx android.OutgoingTransitionContext, sourceVariation string) string {
+	if tag, ok := ctx.DepTag().(apexTransitionTag); ok {
+		return tag.ApexTransition()
+	}
 	return sourceVariation
 }
 
diff --git a/apex/apex_test.go b/apex/apex_test.go
index 987cb69..8877675 100644
--- a/apex/apex_test.go
+++ b/apex/apex_test.go
@@ -5633,7 +5633,7 @@
 		// prebuilt_apex module always depends on the prebuilt, and so it doesn't
 		// find the dex boot jar in it. We either need to disable the source libfoo
 		// or make the prebuilt libfoo preferred.
-		testDexpreoptWithApexes(t, bp, "module libfoo does not provide a dex boot jar", preparer, fragment)
+		testDexpreoptWithApexes(t, bp, `module "platform-bootclasspath" variant ".*": module "libfoo" from platform is not allowed in the apex boot jars list`, preparer, fragment)
 		// dexbootjar check is skipped if AllowMissingDependencies is true
 		preparerAllowMissingDeps := android.GroupFixturePreparers(
 			preparer,
diff --git a/apex/platform_bootclasspath_test.go b/apex/platform_bootclasspath_test.go
index 8b5fce9..6ebd78f 100644
--- a/apex/platform_bootclasspath_test.go
+++ b/apex/platform_bootclasspath_test.go
@@ -561,16 +561,13 @@
 		// Not a prebuilt as no prebuilt existed when it was added.
 		"platform:legacy.core.platform.api.stubs.exportable",
 
-		// The platform_bootclasspath intentionally adds dependencies on both source and prebuilt
-		// modules when available as it does not know which one will be preferred.
-		"myapex:foo",
+		// The prebuilt.
 		"myapex:prebuilt_foo",
 
 		// Only a source module exists.
 		"myapex:bar",
 
 		// The fragments.
-		"myapex:mybootclasspath-fragment",
 		"myapex:prebuilt_mybootclasspath-fragment",
 
 		// Impl lib of sdk_library for transitive srcjar generation
@@ -665,7 +662,7 @@
 		prepareForTestWithMyapex,
 		java.FixtureConfigureApexBootJars("myapex:foo"),
 	).ExtendWithErrorHandler(android.FixtureExpectsAtLeastOneErrorMatchingPattern(
-		`dependency "foo" of "myplatform-bootclasspath" missing variant`)).
+		`module "myplatform-bootclasspath" variant ".*": module "foo" from platform is not allowed in the apex boot jars list`)).
 		RunTestWithBp(t, `
 			apex {
 				name: "myapex",