diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index d07edefcffa..6cad3b94e5e 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -4171,6 +4171,10 @@ Error BitcodeReader::parseFunctionBody(Function *F) {
           popValue(Record, OpNum, NextValueNo, LHS->getType(), RHS))
         return error("Invalid record");
 
+      if (OpNum >= Record.size())
+        return error(
+            "Invalid record: operand number exceeded available operands");
+
       unsigned PredVal = Record[OpNum];
       bool IsFP = LHS->getType()->isFPOrFPVectorTy();
       FastMathFlags FMF;
diff --git a/test/Bitcode/Inputs/invalid-fcmp-opnum.bc b/test/Bitcode/Inputs/invalid-fcmp-opnum.bc
new file mode 100644
index 00000000000..454a14b8611
Binary files /dev/null and b/test/Bitcode/Inputs/invalid-fcmp-opnum.bc differ
diff --git a/test/Bitcode/invalid.test b/test/Bitcode/invalid.test
index 2a9af0626c6..d1f9d7c0874 100644
--- a/test/Bitcode/invalid.test
+++ b/test/Bitcode/invalid.test
@@ -235,3 +235,8 @@ RUN: not llvm-dis -disable-output %p/Inputs/invalid-nonpointer-atomicrmw.bc 2>&1
 RUN:   FileCheck --check-prefix=NONPOINTER-ATOMICRMW %s
 
 NONPOINTER-ATOMICRMW: Invalid record
+
+RUN: not llvm-dis -disable-output %p/Inputs/invalid-fcmp-opnum.bc 2>&1 | \
+RUN:   FileCheck --check-prefix=INVALID-FCMP-OPNUM %s
+
+INVALID-FCMP-OPNUM: Invalid record: operand number exceeded available operands