diff --git a/js/src/jit/arm/MacroAssembler-arm.cpp b/js/src/jit/arm/MacroAssembler-arm.cpp
index 716418b802f..a0e45c4e103 100644
--- a/js/src/jit/arm/MacroAssembler-arm.cpp
+++ b/js/src/jit/arm/MacroAssembler-arm.cpp
@@ -3876,7 +3876,7 @@ MacroAssemblerARMCompat::callWithABIPre(uint32_t *stackAdjust, bool callFromAsmJ
     if (useHardFpABI())
         *stackAdjust += 2*((usedFloatSlots_ > NumFloatArgRegs) ? usedFloatSlots_ - NumFloatArgRegs : 0) * sizeof(intptr_t);
 #endif
-    uint32_t alignmentAtPrologue = (callFromAsmJS) ? AlignmentAtAsmJSPrologue : 0;
+    uint32_t alignmentAtPrologue = callFromAsmJS ? AlignmentAtAsmJSPrologue : 0;
 
     if (!dynamicAlignment_) {
         *stackAdjust += ComputeByteAlignment(framePushed_ + *stackAdjust + alignmentAtPrologue,
diff --git a/js/src/jit/mips/Assembler-mips.h b/js/src/jit/mips/Assembler-mips.h
index 7754a4cd7d3..33910ad42e7 100644
--- a/js/src/jit/mips/Assembler-mips.h
+++ b/js/src/jit/mips/Assembler-mips.h
@@ -153,8 +153,7 @@ static const uint32_t CodeAlignment = 4;
 static const bool StackKeptAligned = true;
 // NativeFrameSize is the size of return adress on stack in AsmJS functions.
 static const uint32_t NativeFrameSize = sizeof(void*);
-static const uint32_t AlignmentAtAsmJSPrologue = 0;
-static const uint32_t AlignmentMidPrologue = NativeFrameSize;
+static const uint32_t AlignmentAtAsmJSPrologue = sizeof(void*);
 
 static const Scale ScalePointer = TimesFour;
 
diff --git a/js/src/jit/mips/CodeGenerator-mips.cpp b/js/src/jit/mips/CodeGenerator-mips.cpp
index 61013caf708..a68a4d5caf5 100644
--- a/js/src/jit/mips/CodeGenerator-mips.cpp
+++ b/js/src/jit/mips/CodeGenerator-mips.cpp
@@ -52,7 +52,7 @@ CodeGeneratorMIPS::generateAsmJSPrologue(Label *stackOverflowLabel)
 {
     JS_ASSERT(gen->compilingAsmJS());
 
-    masm.Push(ra);
+    masm.push(ra);
 
     // The asm.js over-recursed handler wants to be able to assume that SP
     // points to the return address, so perform the check after pushing ra but
@@ -84,18 +84,12 @@ CodeGeneratorMIPS::generateEpilogue()
     }
 #endif
 
-    if (gen->compilingAsmJS()) {
-        // Pop the stack we allocated at the start of the function.
+    if (gen->compilingAsmJS())
         masm.freeStack(frameDepth_);
-        masm.Pop(ra);
-        masm.abiret();
-        MOZ_ASSERT(masm.framePushed() == 0);
-    } else {
-        // Pop the stack we allocated at the start of the function.
+    else
         masm.freeStack(frameSize());
-        MOZ_ASSERT(masm.framePushed() == 0);
-        masm.ret();
-    }
+    JS_ASSERT(masm.framePushed() == 0);
+    masm.ret();
     return true;
 }
 
@@ -989,14 +983,8 @@ CodeGeneratorMIPS::toMoveOperand(const LAllocation *a) const
     if (a->isFloatReg()) {
         return MoveOperand(ToFloatRegister(a));
     }
-    MOZ_ASSERT((ToStackOffset(a) & 3) == 0);
     int32_t offset = ToStackOffset(a);
-
-    // The way the stack slots work, we assume that everything from
-    // depth == 0 downwards is writable. However, since our frame is included
-    // in this, ensure that the frame gets skipped.
-    if (gen->compilingAsmJS())
-        offset -= AlignmentMidPrologue;
+    MOZ_ASSERT((offset & 3) == 0);
 
     return MoveOperand(StackPointer, offset);
 }
diff --git a/js/src/jit/mips/CodeGenerator-mips.h b/js/src/jit/mips/CodeGenerator-mips.h
index b8227b1a0a2..aad26560e1c 100644
--- a/js/src/jit/mips/CodeGenerator-mips.h
+++ b/js/src/jit/mips/CodeGenerator-mips.h
@@ -33,12 +33,6 @@ class CodeGeneratorMIPS : public CodeGeneratorShared
         MOZ_ASSERT(a.isMemory());
         int32_t offset = ToStackOffset(&a);
 
-        // The way the stack slots work, we assume that everything from
-        // depth == 0 downwards is writable however, since our frame is
-        // included in this, ensure that the frame gets skipped.
-        if (gen->compilingAsmJS())
-            offset -= AlignmentMidPrologue;
-
         return Address(StackPointer, offset);
     }
 
@@ -55,12 +49,6 @@ class CodeGeneratorMIPS : public CodeGeneratorShared
         MOZ_ASSERT(a.isMemory());
         int32_t offset = ToStackOffset(&a);
 
-        // The way the stack slots work, we assume that everything from
-        // depth == 0 downwards is writable however, since our frame is
-        // included in this, ensure that the frame gets skipped.
-        if (gen->compilingAsmJS())
-            offset -= AlignmentMidPrologue;
-
         return Operand(StackPointer, offset);
     }
     inline Operand ToOperand(const LAllocation *a) {
diff --git a/js/src/jit/mips/MacroAssembler-mips.cpp b/js/src/jit/mips/MacroAssembler-mips.cpp
index ee5771cf2f0..a85c07e71d5 100644
--- a/js/src/jit/mips/MacroAssembler-mips.cpp
+++ b/js/src/jit/mips/MacroAssembler-mips.cpp
@@ -3141,7 +3141,7 @@ MacroAssemblerMIPSCompat::alignPointerUp(Register src, Register dest, uint32_t a
 }
 
 void
-MacroAssemblerMIPSCompat::callWithABIPre(uint32_t *stackAdjust)
+MacroAssemblerMIPSCompat::callWithABIPre(uint32_t *stackAdjust, bool callFromAsmJS)
 {
     MOZ_ASSERT(inCall_);
 
@@ -3152,10 +3152,13 @@ MacroAssemblerMIPSCompat::callWithABIPre(uint32_t *stackAdjust)
                     usedArgSlots_ * sizeof(intptr_t) :
                     NumIntArgRegs * sizeof(intptr_t);
 
+    uint32_t alignmentAtPrologue = callFromAsmJS ? AlignmentAtAsmJSPrologue : 0;
+
     if (dynamicAlignment_) {
         *stackAdjust += ComputeByteAlignment(*stackAdjust, StackAlignment);
     } else {
-        *stackAdjust += ComputeByteAlignment(framePushed_ + *stackAdjust, StackAlignment);
+        *stackAdjust += ComputeByteAlignment(framePushed_ + alignmentAtPrologue + *stackAdjust,
+                                             StackAlignment);
     }
 
     reserveStack(*stackAdjust);
@@ -3257,7 +3260,7 @@ void
 MacroAssemblerMIPSCompat::callWithABI(AsmJSImmPtr imm, MoveOp::Type result)
 {
     uint32_t stackAdjust;
-    callWithABIPre(&stackAdjust);
+    callWithABIPre(&stackAdjust, /* callFromAsmJS = */ true);
     call(imm);
     callWithABIPost(stackAdjust, result);
 }
diff --git a/js/src/jit/mips/MacroAssembler-mips.h b/js/src/jit/mips/MacroAssembler-mips.h
index 82f1b024e53..0cc3c710a70 100644
--- a/js/src/jit/mips/MacroAssembler-mips.h
+++ b/js/src/jit/mips/MacroAssembler-mips.h
@@ -422,7 +422,9 @@ class MacroAssemblerMIPSCompat : public MacroAssemblerMIPS
     }
 
     void appendCallSite(const CallSiteDesc &desc) {
-        enoughMemory_ &= append(CallSite(desc, currentOffset(), framePushed_));
+        // Add an extra sizeof(void*) to include the return address that was
+        // pushed by the call instruction (see CallSite::stackDepth).
+        enoughMemory_ &= append(CallSite(desc, currentOffset(), framePushed_ + sizeof(void*)));
     }
 
     void call(const CallSiteDesc &desc, const Register reg) {
@@ -1235,7 +1237,7 @@ public:
     bool buildOOLFakeExitFrame(void *fakeReturnAddr);
 
   private:
-    void callWithABIPre(uint32_t *stackAdjust);
+    void callWithABIPre(uint32_t *stackAdjust, bool callFromAsmJS = false);
     void callWithABIPost(uint32_t stackAdjust, MoveOp::Type result);
 
   public: