diff --git a/js/src/jit/BaselineJIT.cpp b/js/src/jit/BaselineJIT.cpp
index 42e1bde06c5..f256f6f89a8 100644
--- a/js/src/jit/BaselineJIT.cpp
+++ b/js/src/jit/BaselineJIT.cpp
@@ -891,6 +891,10 @@ jit::FinishDiscardBaselineScript(FreeOp *fop, JSScript *script)
         // Reset |active| flag so that we don't need a separate script
         // iteration to unmark them.
         script->baselineScript()->resetActive();
+
+        // The baseline caches have been wiped out, so the script will need to
+        // warm back up before it can be inlined during Ion compilation.
+        script->baselineScript()->clearIonCompiledOrInlined();
         return;
     }
 
diff --git a/js/src/jit/BaselineJIT.h b/js/src/jit/BaselineJIT.h
index 2eaff1a4a80..357afa148f0 100644
--- a/js/src/jit/BaselineJIT.h
+++ b/js/src/jit/BaselineJIT.h
@@ -151,7 +151,12 @@ struct BaselineScript
 
         // Flag set when compiled for use for debug mode. Handles various
         // Debugger hooks and compiles toggled calls for traps.
-        DEBUG_MODE = 1 << 3
+        DEBUG_MODE = 1 << 3,
+
+        // Flag set if this script has ever been Ion compiled, either directly
+        // or inlined into another script. This is cleared when the script's
+        // type information or caches are cleared.
+        ION_COMPILED_OR_INLINED = 1 << 4
     };
 
   private:
@@ -229,6 +234,16 @@ struct BaselineScript
         return flags_ & DEBUG_MODE;
     }
 
+    void setIonCompiledOrInlined() {
+        flags_ |= ION_COMPILED_OR_INLINED;
+    }
+    void clearIonCompiledOrInlined() {
+        flags_ &= ~ION_COMPILED_OR_INLINED;
+    }
+    bool ionCompiledOrInlined() const {
+        return flags_ & ION_COMPILED_OR_INLINED;
+    }
+
     uint32_t prologueOffset() const {
         return prologueOffset_;
     }
diff --git a/js/src/jit/IonBuilder.cpp b/js/src/jit/IonBuilder.cpp
index fb89a5a623e..33d0f7dd894 100644
--- a/js/src/jit/IonBuilder.cpp
+++ b/js/src/jit/IonBuilder.cpp
@@ -148,6 +148,9 @@ IonBuilder::IonBuilder(JSContext *analysisContext, CompileCompartment *comp,
 
     JS_ASSERT(script()->hasBaselineScript() == (info->executionMode() != ArgumentsUsageAnalysis));
     JS_ASSERT(!!analysisContext == (info->executionMode() == DefinitePropertiesAnalysis));
+
+    if (!info->executionModeIsAnalysis())
+        script()->baselineScript()->setIonCompiledOrInlined();
 }
 
 void
@@ -4202,6 +4205,7 @@ IonBuilder::makeInliningDecision(JSFunction *target, CallInfo &callInfo)
         // type information, except for definite properties analysis,
         // as the caller has not run yet.
         if (targetScript->getUseCount() < optimizationInfo().usesBeforeInlining() &&
+            !targetScript->baselineScript()->ionCompiledOrInlined() &&
             info().executionMode() != DefinitePropertiesAnalysis)
         {
             return DontInline(targetScript, "Vetoed: callee is insufficiently hot.");