diff --git a/lib/Fuzzer/FuzzerCorpus.h b/lib/Fuzzer/FuzzerCorpus.h
index c4d1db74014..218ae5b6ac4 100644
--- a/lib/Fuzzer/FuzzerCorpus.h
+++ b/lib/Fuzzer/FuzzerCorpus.h
@@ -139,6 +139,9 @@ class InputCorpus {
   }
 
   void Replace(InputInfo *II, const Unit &U) {
+    assert(II->U.size());
+    Hashes.erase(Sha1ToString(II->Sha1));
+    DeleteFile(*II);
     ComputeSHA1(U.data(), U.size(), II->Sha1);
     Hashes.insert(Sha1ToString(II->Sha1));
     II->U = U;
@@ -182,10 +185,14 @@ class InputCorpus {
     Printf("\n");
   }
 
-  void DeleteInput(size_t Idx) {
-    InputInfo &II = *Inputs[Idx];
+  void DeleteFile(const InputInfo &II) {
     if (!OutputCorpus.empty() && II.MayDeleteFile)
       RemoveFile(DirPlusFile(OutputCorpus, Sha1ToString(II.Sha1)));
+  }
+
+  void DeleteInput(size_t Idx) {
+    InputInfo &II = *Inputs[Idx];
+    DeleteFile(II);
     Unit().swap(II.U);
     if (FeatureDebug)
       Printf("EVICTED %zd\n", Idx);
diff --git a/lib/Fuzzer/test/reduce_inputs.test b/lib/Fuzzer/test/reduce_inputs.test
index cc803d789d8..a4a5c57123d 100644
--- a/lib/Fuzzer/test/reduce_inputs.test
+++ b/lib/Fuzzer/test/reduce_inputs.test
@@ -1,2 +1,13 @@
+# Test -reduce_inputs=1
+
+RUN: rm -rf %t/C
+RUN: mkdir -p %t/C
+RUN: LLVMFuzzer-ShrinkControlFlowSimpleTest  -exit_on_item=0eb8e4ed029b774d80f2b66408203801cb982a60   -reduce_inputs=1 -runs=1000000 %t/C 2>&1 | FileCheck %s
 CHECK: INFO: found item with checksum '0eb8e4ed029b774d80f2b66408203801cb982a60'
-RUN: LLVMFuzzer-ShrinkControlFlowSimpleTest  -exit_on_item=0eb8e4ed029b774d80f2b66408203801cb982a60   -reduce_inputs=1 -runs=1000000 2>&1 | FileCheck %s
+
+# Test that reduce_inputs deletes redundant files in the corpus.
+RUN: LLVMFuzzer-ShrinkControlFlowSimpleTest -runs=0 %t/C 2>&1 | FileCheck %s --check-prefix=COUNT
+COUNT: READ units: 3
+
+
+