Index: ./lib/IR/Verifier.cpp      
===================================================================
--- ./lib/IR/Verifier.cpp      
+++ ./lib/IR/Verifier.cpp      
@@ -871,7 +871,8 @@
 
 void Verifier::visitDIBasicType(const DIBasicType &N) {
   AssertDI(N.getTag() == dwarf::DW_TAG_base_type ||
-               N.getTag() == dwarf::DW_TAG_unspecified_type,
+               N.getTag() == dwarf::DW_TAG_unspecified_type ||
+               N.getTag() == dwarf::DW_TAG_string_type,
            "invalid tag", &N);
 }
 
Index: ./test/DebugInfo/string-type.ll     
===================================================================
--- ./test/DebugInfo/string-type.ll     
+++ ./test/DebugInfo/string-type.ll     
@@ -0,0 +1,28 @@
+; RUN: %llc_dwarf %s -filetype=obj -o %t
+; RUN: llvm-dwarfdump -debug-dump=info %t | FileCheck %s
+; CHECK: DW_TAG_string_type [4]
+; REQUIRES: default_triple
+
+declare void @llvm.dbg.declare(metadata, metadata, metadata)
+define void @mysub_(i64* %a, i64* %ab, i64* %b, i32 %.U0003.arg, i32 %.U0004.arg, i32 %.U0005.arg) #0 !dbg !26 {
+       call void @llvm.dbg.declare (metadata i64* %a, metadata !30, metadata !31), !dbg !29
+       ret void, !dbg !38
+}
+!llvm.module.flags = !{ !1, !2 }
+!llvm.dbg.cu = !{ !10 }
+!1 = !{ i32 2, !"Dwarf Version", i32 2 }
+!2 = !{ i32 1, !"Debug Info Version", i32 3 }
+!3 = !DIFile(filename: "dwarf-string-type.f90", directory: "/")
+!5 = !{  }
+!7 = !{ !26 }
+!10 = distinct !DICompileUnit(file: !3, language: DW_LANG_Fortran90, producer: "flang", enums: !5, retainedTypes: !5, globals: !5, emissionKind: FullDebug, imports: !5)
+!21 = !DIBasicType(tag: DW_TAG_string_type, name: "character", size: 8, align: 8, encoding: DW_ATE_signed)
+!23 = !{ null, !21 }
+!24 = !DISubroutineType(types: !23)
+!26 = distinct !DISubprogram(file: !3, scope: !10, name: "mysub", line: 10, type: !24, isDefinition: true, unit: !10, variables: !5, scopeLine: 10)
+!27 = !DILocation(scope: !26)
+!28 = !DILexicalBlock(file: !3, scope: !26, line: 10, column: 1)
+!29 = !DILocation(scope: !28)
+!30 = !DILocalVariable(scope: !26, name: "a", arg: 1, file: !3, type: !21)
+!31 = !DIExpression()
+!38 = !DILocation(line: 13, column: 1, scope: !28)