diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 1614d23d988..1000ba60367 100644
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -4287,7 +4287,8 @@ Instruction *InstCombiner::visitOr(BinaryOperator &I) {
   if (FCmpInst *LHS = dyn_cast<FCmpInst>(I.getOperand(0))) {
     if (FCmpInst *RHS = dyn_cast<FCmpInst>(I.getOperand(1))) {
       if (LHS->getPredicate() == FCmpInst::FCMP_UNO &&
-          RHS->getPredicate() == FCmpInst::FCMP_UNO)
+          RHS->getPredicate() == FCmpInst::FCMP_UNO && 
+          LHS->getOperand(0)->getType() == RHS->getOperand(0)->getType())
         if (ConstantFP *LHSC = dyn_cast<ConstantFP>(LHS->getOperand(1)))
           if (ConstantFP *RHSC = dyn_cast<ConstantFP>(RHS->getOperand(1))) {
             // If either of the constants are nans, then the whole thing returns
diff --git a/test/Transforms/InstCombine/2008-02-28-OrFCmpCrash.ll b/test/Transforms/InstCombine/2008-02-28-OrFCmpCrash.ll
new file mode 100644
index 00000000000..ea024039562
--- /dev/null
+++ b/test/Transforms/InstCombine/2008-02-28-OrFCmpCrash.ll
@@ -0,0 +1,16 @@
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis
+; rdar://5771353
+
+define float @test(float %x, x86_fp80 %y) nounwind readonly  {
+entry:
+	%tmp67 = fcmp uno x86_fp80 %y, 0xK00000000000000000000		; <i1> [#uses=1]
+	%tmp71 = fcmp uno float %x, 0.000000e+00		; <i1> [#uses=1]
+	%bothcond = or i1 %tmp67, %tmp71		; <i1> [#uses=1]
+	br i1 %bothcond, label %bb74, label %bb80
+
+bb74:		; preds = %entry
+	ret float 0.000000e+00
+
+bb80:		; preds = %entry
+	ret float 0.000000e+00
+}