diff --git a/COFF/Driver.cpp b/COFF/Driver.cpp
index c5c8d5c..cf96ecb 100644
--- a/COFF/Driver.cpp
+++ b/COFF/Driver.cpp
@@ -157,9 +157,8 @@
   auto strategy = std::launch::deferred;
 #endif
   return std::async(strategy, [=]() {
-    auto mbOrErr = MemoryBuffer::getFile(path,
-                                         /*FileSize*/ -1,
-                                         /*RequiresNullTerminator*/ false);
+    auto mbOrErr = MemoryBuffer::getFile(path, /*IsText=*/false,
+                                         /*RequiresNullTerminator=*/false);
     if (!mbOrErr)
       return MBErrPair{nullptr, mbOrErr.getError()};
     return MBErrPair{std::move(*mbOrErr), std::error_code()};
@@ -829,7 +828,7 @@
   // If the import library already exists, replace it only if the contents
   // have changed.
   ErrorOr<std::unique_ptr<MemoryBuffer>> oldBuf = MemoryBuffer::getFile(
-      path, /*FileSize*/ -1, /*RequiresNullTerminator*/ false);
+      path, /*IsText=*/false, /*RequiresNullTerminator=*/false);
   if (!oldBuf) {
     handleError(writeImportLibrary(libName, path, exports, config->machine,
                                    config->mingw));
@@ -849,7 +848,7 @@
   }
 
   std::unique_ptr<MemoryBuffer> newBuf = check(MemoryBuffer::getFile(
-      tmpName, /*FileSize*/ -1, /*RequiresNullTerminator*/ false));
+      tmpName, /*IsText=*/false, /*RequiresNullTerminator=*/false));
   if ((*oldBuf)->getBuffer() != newBuf->getBuffer()) {
     oldBuf->reset();
     handleError(errorCodeToError(sys::fs::rename(tmpName, path)));
@@ -859,8 +858,11 @@
 }
 
 static void parseModuleDefs(StringRef path) {
-  std::unique_ptr<MemoryBuffer> mb = CHECK(
-      MemoryBuffer::getFile(path, -1, false, true), "could not open " + path);
+  std::unique_ptr<MemoryBuffer> mb =
+      CHECK(MemoryBuffer::getFile(path, /*IsText=*/false,
+                                  /*RequiresNullTerminator=*/false,
+                                  /*IsVolatile=*/true),
+            "could not open " + path);
   COFFModuleDefinition m = check(parseCOFFModuleDefinition(
       mb->getMemBufferRef(), config->machine, config->mingw));
 
@@ -948,8 +950,11 @@
 
   // Open a file.
   StringRef path = arg.substr(1);
-  std::unique_ptr<MemoryBuffer> mb = CHECK(
-      MemoryBuffer::getFile(path, -1, false, true), "could not open " + path);
+  std::unique_ptr<MemoryBuffer> mb =
+      CHECK(MemoryBuffer::getFile(path, /*IsText=*/false,
+                                  /*RequiresNullTerminator=*/false,
+                                  /*IsVolatile=*/true),
+            "could not open " + path);
 
   // Parse a file. An order file contains one symbol per line.
   // All symbols that were not present in a given order file are
@@ -973,8 +978,11 @@
 }
 
 static void parseCallGraphFile(StringRef path) {
-  std::unique_ptr<MemoryBuffer> mb = CHECK(
-      MemoryBuffer::getFile(path, -1, false, true), "could not open " + path);
+  std::unique_ptr<MemoryBuffer> mb =
+      CHECK(MemoryBuffer::getFile(path, /*IsText=*/false,
+                                  /*RequiresNullTerminator=*/false,
+                                  /*IsVolatile=*/true),
+            "could not open " + path);
 
   // Build a map from symbol name to section.
   DenseMap<StringRef, Symbol *> map;
diff --git a/COFF/DriverUtils.cpp b/COFF/DriverUtils.cpp
index 1996442..1e8cbe8 100644
--- a/COFF/DriverUtils.cpp
+++ b/COFF/DriverUtils.cpp
@@ -350,7 +350,7 @@
   // is called (you cannot remove an opened file on Windows.)
   std::unique_ptr<MemoryBuffer> getMemoryBuffer() {
     // IsVolatile=true forces MemoryBuffer to not use mmap().
-    return CHECK(MemoryBuffer::getFile(path, /*FileSize=*/-1,
+    return CHECK(MemoryBuffer::getFile(path, /*IsText=*/false,
                                        /*RequiresNullTerminator=*/false,
                                        /*IsVolatile=*/true),
                  "could not open " + path);
diff --git a/ELF/InputFiles.cpp b/ELF/InputFiles.cpp
index 6cf668d..1f1ff22 100644
--- a/ELF/InputFiles.cpp
+++ b/ELF/InputFiles.cpp
@@ -115,7 +115,8 @@
   log(path);
   config->dependencyFiles.insert(llvm::CachedHashString(path));
 
-  auto mbOrErr = MemoryBuffer::getFile(path, -1, false);
+  auto mbOrErr = MemoryBuffer::getFile(path, /*IsText=*/false,
+                                       /*RequiresNullTerminator=*/false);
   if (auto ec = mbOrErr.getError()) {
     error("cannot open " + path + ": " + ec.message());
     return None;