Index: llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
===================================================================
--- llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
+++ llvm/lib/DebugInfo/DWARF/DWARFUnit.cpp
@@ -329,7 +329,7 @@
 template<typename ListTableType>
 static Expected<ListTableType>
 parseListTableHeader(DWARFDataExtractor &DA, uint64_t Offset,
-                        DwarfFormat Format) {
+                        DwarfFormat Format, uint64_t CUOffset) {
   // We are expected to be called with Offset 0 or pointing just past the table
   // header. Correct Offset in the latter case so that it points to the start
   // of the header.
@@ -342,8 +342,15 @@
     Offset -= HeaderSize;
   }
   ListTableType Table;
+  uint64_t StartOffset = Offset;
   if (Error E = Table.extractHeaderAndOffsets(DA, &Offset))
     return std::move(E);
+  if (Format != Table.getFormat())
+    return createStringError(errc::invalid_argument,
+                             "mismatched DWARF formats between "
+                             "CU at offset 0x%" PRIx64 " "
+                             "and list table with base = 0x%" PRIx64 "\n",
+                             CUOffset, StartOffset);
   return Table;
 }
 
@@ -497,7 +504,7 @@
       DWARFDataExtractor RangesDA(Context.getDWARFObj(), *RangeSection,
                                   isLittleEndian, 0);
       auto TableOrError = parseListTableHeader<DWARFDebugRnglistTable>(
-          RangesDA, RangeSectionBase, Header.getFormat());
+          RangesDA, RangeSectionBase, Header.getFormat(), Header.getOffset());
       if (!TableOrError)
         return createStringError(errc::invalid_argument,
                                  "parsing a range list table: " +
@@ -587,7 +594,7 @@
     DWARFDataExtractor RangesDA(Context.getDWARFObj(), *RangeSection,
                                 isLittleEndian, 0);
     if (auto TableOrError = parseListTableHeader<DWARFDebugRnglistTable>(
-            RangesDA, RangeSectionBase, Header.getFormat()))
+            RangesDA, RangeSectionBase, Header.getFormat(), Header.getOffset()))
       DWO->RngListTable = TableOrError.get();
     else
       WithColor::error() << "parsing a range list table: "
Index: llvm/test/DebugInfo/X86/dwarfdump-rnglists-format-mismatch.s
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/X86/dwarfdump-rnglists-format-mismatch.s
@@ -0,0 +1,42 @@
+# RUN: llvm-mc -triple x86_64-unknown-linux %s -filetype=obj -o - | \
+# RUN:   llvm-dwarfdump -debug-info - 2>&1 > /dev/null | \
+# RUN:   FileCheck %s
+
+        .section .debug_abbrev.dwo,"",@progbits
+        .byte 0x01      # Abbrev code
+        .byte 0x11      # DW_TAG_compile_unit
+        .byte 0x00      # DW_CHILDREN_no
+        .byte 0x55      # DW_AT_ranges
+        .byte 0x23      # DW_FORM_rnglistx
+        .byte 0x00      # EOM(1)
+        .byte 0x00      # EOM(2)
+        .byte 0x00      # EOM(3)
+
+        .section .debug_info.dwo,"",@progbits
+        .long .LCUend - .LCUversion     # Length of Unit
+.LCUversion:
+        .short 5                        # DWARF version number
+        .byte 5                         # DW_UT_split_compile
+        .byte 4                         # Address Size (in bytes)
+        .long 0                         # Offset Into Abbrev Section
+        .quad 0                         # DWO Id
+        .byte 1                         # Abbreviation code
+        .uleb128 0                      # DW_AT_ranges
+.LCUend:
+
+        .section .debug_rnglists.dwo,"",@progbits
+        .long 0xffffffff                # DWARF64 mark
+        .quad .LRTend - .LRTversion     # table length
+.LRTversion:
+        .short 5                        # version
+        .byte 4                         # address size
+        .byte 0                         # segment selector size
+        .long 1                         # offset entry count
+.LRTbase:
+        .quad .LRTlist0 - .LRTbase
+.LRTlist0:
+        .byte 0                         # DW_RLE_end_of_list
+.LRTend:
+
+# CHECK: error: parsing a range list table: mismatched DWARF formats between
+# CHECK-SAME: CU at offset 0x0 and list table with base = 0x0