diff --git a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
--- a/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
+++ b/llvm/lib/Target/X86/AsmParser/X86AsmParser.cpp
@@ -3105,7 +3105,8 @@
        (PatchedName.startswith("j") &&
         ParseConditionCode(PatchedName.substr(1)) != X86::COND_INVALID))) {
     StringRef NextTok = Parser.getTok().getString();
-    if (NextTok == "short") {
+    if (Parser.isParsingMasm() ? NextTok.equals_lower("short")
+                               : NextTok == "short") {
       SMLoc NameEndLoc =
           NameLoc.getFromPointer(NameLoc.getPointer() + Name.size());
       // Eat the short keyword.
diff --git a/llvm/test/tools/llvm-ml/jmp_short.asm b/llvm/test/tools/llvm-ml/jmp_short.asm
new file mode 100644
--- /dev/null
+++ b/llvm/test/tools/llvm-ml/jmp_short.asm
@@ -0,0 +1,21 @@
+; RUN: llvm-ml -filetype=s %s /Fo - | FileCheck %s
+
+.code
+
+t1:
+  jmp short t1_label
+  jmp SHORT t1_label
+  JmP Short t1_label
+  JMP SHORT t1_label
+  mov eax, eax
+t1_label:
+  ret
+
+; CHECK-LABEL: t1:
+; CHECK-NEXT: jmp t1_label
+; CHECK-NEXT: jmp t1_label
+; CHECK-NEXT: jmp t1_label
+; CHECK-NEXT: jmp t1_label
+; CHECK-NEXT: mov eax, eax
+
+end