diff --git a/lib/Driver/Compilation.cpp b/lib/Driver/Compilation.cpp
index b4829ab4b402b..cf53235560519 100644
--- a/lib/Driver/Compilation.cpp
+++ b/lib/Driver/Compilation.cpp
@@ -2060,10 +2060,7 @@ void Compilation::sortJobsToMatchCompilationInputs(
     if (const CompileJobAction *CJA =
             dyn_cast<CompileJobAction>(&J->getSource())) {
       const InputAction *IA = CJA->findSingleSwiftInput();
-      auto R =
-          jobsByInput.insert(std::make_pair(IA->getInputArg().getValue(), J));
-      assert(R.second);
-      (void)R;
+      jobsByInput.insert(std::make_pair(IA->getInputArg().getValue(), J));
     } else
       sortedJobs.push_back(J);
   }
diff --git a/lib/Driver/FineGrainedDependencyDriverGraph.cpp b/lib/Driver/FineGrainedDependencyDriverGraph.cpp
index bc1cda3e359f7..8725924d68b27 100644
--- a/lib/Driver/FineGrainedDependencyDriverGraph.cpp
+++ b/lib/Driver/FineGrainedDependencyDriverGraph.cpp
@@ -196,6 +196,8 @@ std::vector<StringRef> ModuleDepGraph::getExternalDependencies() const {
 }
 
 // Add every (swiftdeps) use of the external dependency to foundJobs.
+// Can return duplicates, but it doesn't break anything, and they will be
+// canonicalized later.
 std::vector<const Job *> ModuleDepGraph::findExternallyDependentUntracedJobs(
     StringRef externalDependency) {
   FrontendStatsTracer tracer(
diff --git a/unittests/Driver/TypeBodyFingerprintsDependencyGraphTests.cpp b/unittests/Driver/TypeBodyFingerprintsDependencyGraphTests.cpp
index c47007edc4297..9e572b0c5fca4 100644
--- a/unittests/Driver/TypeBodyFingerprintsDependencyGraphTests.cpp
+++ b/unittests/Driver/TypeBodyFingerprintsDependencyGraphTests.cpp
@@ -13,6 +13,8 @@
 // would be excluded in the coarse-grained graph. But since these will be jobs
 // that have already been scheduled, downstream mechanisms will filter them out.
 
+// \c \c findExternallyDependentUntracedJobs may also return duplicates
+
 // To debug a test, create the \c ModuleDepGraph and pass true as the second
 // argument to the constructor, then find the dot files in the directory
 // where the tests run,