diff --git a/llvm/test/tools/llvm-profdata/text-dump.test b/llvm/test/tools/llvm-profdata/text-dump.test
--- a/llvm/test/tools/llvm-profdata/text-dump.test
+++ b/llvm/test/tools/llvm-profdata/text-dump.test
@@ -2,6 +2,7 @@
 
 RUN: llvm-profdata show --all-functions -counts --text %p/Inputs/basic.proftext > %t-basic.proftext1
 RUN: llvm-profdata merge -o %t-basic.proftext2 --text  %p/Inputs/basic.proftext
+RUN: llvm-profdata merge --text %p/Inputs/basic.proftext | diff %t-basic.proftext2 -
 
 RUN: llvm-profdata merge -binary -o %t-basic.profdata1 %t-basic.proftext1
 RUN: llvm-profdata merge -o %t-basic.profdata2 %t-basic.proftext2
diff --git a/llvm/tools/llvm-profdata/llvm-profdata.cpp b/llvm/tools/llvm-profdata/llvm-profdata.cpp
--- a/llvm/tools/llvm-profdata/llvm-profdata.cpp
+++ b/llvm/tools/llvm-profdata/llvm-profdata.cpp
@@ -316,6 +316,8 @@
     if (Error E = Writer.writeText(Output))
       warn(std::move(E));
   } else {
+    if (Output.is_displayed())
+      exitWithError("cannot write a non-text format profile to the terminal");
     if (Error E = Writer.write(Output))
       warn(std::move(E));
   }
@@ -326,9 +328,6 @@
                               StringRef OutputFilename,
                               ProfileFormat OutputFormat, bool OutputSparse,
                               unsigned NumThreads, FailureMode FailMode) {
-  if (OutputFilename.compare("-") == 0)
-    exitWithError("cannot write indexed profdata format to stdout");
-
   if (OutputFormat != PF_Binary && OutputFormat != PF_Compact_Binary &&
       OutputFormat != PF_Ext_Binary && OutputFormat != PF_Text)
     exitWithError("unknown format is specified");
@@ -863,8 +862,7 @@
   cl::alias RemappingFileA("r", cl::desc("Alias for --remapping-file"),
                            cl::aliasopt(RemappingFile));
   cl::opt<std::string> OutputFilename("output", cl::value_desc("output"),
-                                      cl::init("-"), cl::Required,
-                                      cl::desc("Output file"));
+                                      cl::init("-"), cl::desc("Output file"));
   cl::alias OutputFilenameA("o", cl::desc("Alias for --output"),
                             cl::aliasopt(OutputFilename));
   cl::opt<ProfileKinds> ProfileKind(