diff --git a/js/src/nanojit/NativeX64.cpp b/js/src/nanojit/NativeX64.cpp
index 3ee96436d14..8b98cd58559 100644
--- a/js/src/nanojit/NativeX64.cpp
+++ b/js/src/nanojit/NativeX64.cpp
@@ -317,7 +317,7 @@ namespace nanojit
         rr = prepResultReg(ins, allow);
         // if this is last use of a in reg, we can re-use result reg
         if (a->isUnusedOrHasUnknownReg()) {
-            ra = findSpecificRegFor(a, rr);
+            ra = findSpecificRegForUnallocated(a, rr);
         } else if (!(allow & rmask(a->getReg()))) {
             // 'a' already has a register assigned, but it's not valid.
             // To make sure floating point operations stay in FPU registers
@@ -471,7 +471,7 @@ namespace nanojit
 
         Register rhsReg = findRegFor(rhs, (GpRegs ^ (rmask(RAX)|rmask(RDX))));
         Register lhsReg = lhs->isUnusedOrHasUnknownReg()
-                          ? findSpecificRegFor(lhs, RAX)
+                          ? findSpecificRegForUnallocated(lhs, RAX)
                           : lhs->getReg();
         emitr(X64_idiv, rhsReg);
         emit8(rexrb(X64_sari | uint64_t(RDX&7)<<48, (Register)0, RDX), 31);
@@ -1207,7 +1207,7 @@ namespace nanojit
         rr = prepResultReg(ins, allow);
         // if this is last use of a in reg, we can re-use result reg
         if (a->isUnusedOrHasUnknownReg()) {
-            ra = findSpecificRegFor(a, rr);
+            ra = findSpecificRegForUnallocated(a, rr);
         } else {
             // 'a' already has a register assigned.  Caller must emit a copy
             // to rr once instr code is generated.  (ie  mov rr,ra ; op rr)
diff --git a/js/src/nanojit/Nativei386.cpp b/js/src/nanojit/Nativei386.cpp
index 4af74273c38..face0abedae 100644
--- a/js/src/nanojit/Nativei386.cpp
+++ b/js/src/nanojit/Nativei386.cpp
@@ -1747,7 +1747,7 @@ namespace nanojit
                 // compare two different numbers
                 int d = findMemFor(rhs);
                 int pop = lhs->isUnusedOrHasUnknownReg();
-                findSpecificRegForUnallocated(lhs, FST0);
+                findSpecificRegFor(lhs, FST0);
                 // lhs is in ST(0) and rhs is on stack
                 FCOM(pop, d, FP);
             }
@@ -1755,7 +1755,7 @@ namespace nanojit
             {
                 // compare n to itself, this is a NaN test.
                 int pop = lhs->isUnusedOrHasUnknownReg();
-                findSpecificRegForUnallocated(lhs, FST0);
+                findSpecificRegFor(lhs, FST0);
                 // value in ST(0)
                 if (pop)
                     FCOMPP();