diff --git a/lib/Support/CachePruning.cpp b/lib/Support/CachePruning.cpp
index 303ad219746..57342288e7d 100644
--- a/lib/Support/CachePruning.cpp
+++ b/lib/Support/CachePruning.cpp
@@ -94,7 +94,7 @@ llvm::parseCachePruningPolicy(StringRef PolicyStr) {
       Policy.MaxSizePercentageOfAvailableSpace = Size;
     } else if (Key == "cache_size_bytes") {
       uint64_t Mult = 1;
-      switch (Value.back()) {
+      switch (tolower(Value.back())) {
       case 'k':
         Mult = 1024;
         Value = Value.drop_back();
diff --git a/unittests/Support/CachePruningTest.cpp b/unittests/Support/CachePruningTest.cpp
index 97d554eabc3..1bb57871925 100644
--- a/unittests/Support/CachePruningTest.cpp
+++ b/unittests/Support/CachePruningTest.cpp
@@ -59,7 +59,7 @@ TEST(CachePruningPolicyParser, MaxSizeBytes) {
   ASSERT_TRUE(bool(P));
   EXPECT_EQ(75u, P->MaxSizePercentageOfAvailableSpace);
   EXPECT_EQ(3u * 1024u * 1024u, P->MaxSizeBytes);
-  P = parseCachePruningPolicy("cache_size_bytes=4g");
+  P = parseCachePruningPolicy("cache_size_bytes=4G");
   ASSERT_TRUE(bool(P));
   EXPECT_EQ(75u, P->MaxSizePercentageOfAvailableSpace);
   EXPECT_EQ(4ull * 1024ull * 1024ull * 1024ull, P->MaxSizeBytes);