diff --git a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
--- a/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
@@ -513,7 +513,6 @@
       }
       OS << "debug_line[" << format("0x%8.8" PRIx64, Parser.getOffset())
          << "]\n";
-      OS.flush();
       if (DumpOpts.Verbose) {
         Parser.parseNext(DumpOpts.WarningHandler, DumpOpts.WarningHandler, &OS);
       } else {
@@ -521,7 +520,6 @@
             Parser.parseNext(DumpOpts.WarningHandler, DumpOpts.WarningHandler);
         LineTable.dump(OS, DumpOpts);
       }
-      OS.flush();
     }
   };
 
diff --git a/llvm/test/tools/llvm-dwarfdump/X86/debug_line_invalid.test b/llvm/test/tools/llvm-dwarfdump/X86/debug_line_invalid.test
--- a/llvm/test/tools/llvm-dwarfdump/X86/debug_line_invalid.test
+++ b/llvm/test/tools/llvm-dwarfdump/X86/debug_line_invalid.test
@@ -4,39 +4,41 @@
 ## Show that a bad length stops parsing of the section.
 # RUN: llvm-mc -triple x86_64-pc-linux %S/Inputs/debug_line_reserved_length.s -filetype=obj -o %t-reserved.o
 # RUN: llvm-dwarfdump -debug-line %t-reserved.o 2>&1 \
-# RUN:   | FileCheck %s --check-prefixes=FIRST,FATAL,RESERVED
+# RUN:   | FileCheck %s --check-prefixes=HEADER,FIRST,FATAL,RESERVED
 # RUN: llvm-dwarfdump -debug-line %t-reserved.o -verbose 2>&1 \
-# RUN:   | FileCheck %s --check-prefixes=FIRST,FATAL,RESERVED
+# RUN:   | FileCheck %s --check-prefixes=HEADER,FIRST,FATAL,RESERVED
 
 ## We only produce warnings for malformed tables after the specified unit if
 ## parsing can continue.
 # RUN: llvm-dwarfdump -debug-line=0 %t-reserved.o 2>&1 \
-# RUN:   | FileCheck %s --check-prefixes=FIRST,NOLATER,RESERVED
+# RUN:   | FileCheck %s --check-prefixes=HEADER,FIRST,NOLATER,RESERVED
 
 ## Stop looking for the specified unit, if a fatally-bad prologue is detected.
 # RUN: llvm-dwarfdump -debug-line=0x4b %t-reserved.o 2>&1 \
-# RUN:   | FileCheck %s --check-prefixes=NOFIRST,NOLATER,RESERVED
+# RUN:   | FileCheck %s --check-prefixes=HEADER,NOFIRST,NOLATER,RESERVED
 
 ## Show that non-fatal errors do not prevent parsing the rest of the section.
 # RUN: llvm-mc -triple x86_64-pc-linux %S/Inputs/debug_line_malformed.s -filetype=obj -o %t-malformed.o
 # RUN: llvm-dwarfdump -debug-line %t-malformed.o 2> %t-malformed.err \
-# RUN:   | FileCheck %s --check-prefixes=FIRST,NONFATAL,LAST --implicit-check-not='debug_line[{{.*}}]'
+# RUN:   | FileCheck %s --check-prefixes=HEADER,FIRST,NONFATAL,LAST --implicit-check-not='debug_line[{{.*}}]'
 # RUN: FileCheck %s --input-file=%t-malformed.err --check-prefixes=ALL,OTHER
 # RUN: llvm-dwarfdump -debug-line %t-malformed.o -verbose 2> %t-malformed-verbose.err \
-# RUN:   | FileCheck %s --check-prefixes=FIRST,VERBOSE,NONFATAL,LAST --implicit-check-not='debug_line[{{.*}}]' \
+# RUN:   | FileCheck %s --check-prefixes=HEADER,FIRST,VERBOSE,NONFATAL,LAST --implicit-check-not='debug_line[{{.*}}]' \
 # RUN:       --implicit-check-not=' DW_LNS' --implicit-check-not=' DW_LNE' --implicit-check-not='address +='
 # RUN: FileCheck %s --input-file=%t-malformed-verbose.err --check-prefixes=ALL,OTHER
 
 ## We should still produce warnings for malformed tables after the specified unit.
 # RUN: llvm-dwarfdump -debug-line=0 %t-malformed.o 2> %t-malformed-off-first.err \
-# RUN:   | FileCheck %s --check-prefixes=FIRST,NOLATER
+# RUN:   | FileCheck %s --check-prefixes=HEADER,FIRST,NOLATER
 # RUN: FileCheck %s --input-file=%t-malformed-off-first.err --check-prefix=ALL
 
 ## Don't stop looking for the later unit if non-fatal issues are found.
 # RUN: llvm-dwarfdump -debug-line=0x419 %t-malformed.o 2> %t-malformed-off-last.err \
-# RUN:   | FileCheck %s --check-prefix=LAST --implicit-check-not='debug_line[{{.*}}]'
+# RUN:   | FileCheck %s --check-prefixes=HEADER,LAST --implicit-check-not='debug_line[{{.*}}]'
 # RUN: FileCheck %s --input-file=%t-malformed-off-last.err --check-prefix=ALL
 
+# HEADER:       .debug_line contents:
+
 # FIRST:        debug_line[0x00000000]
 # VERBOSE:      DW_LNE_set_address (0x000000000badbeef)
 # VERBOSE-NEXT: DW_LNE_end_sequence