diff --git a/src/common/PackedEnums.h b/src/common/PackedEnums.h
index 301a56736..e4c3d2496 100644
--- a/src/common/PackedEnums.h
+++ b/src/common/PackedEnums.h
@@ -110,8 +110,18 @@ class PackedEnumMap
     constexpr bool empty() const noexcept { return mPrivateData.empty(); }
 
     // element access:
-    reference operator[](E n) { return mPrivateData[static_cast<UnderlyingType>(n)]; }
-    const_reference operator[](E n) const { return mPrivateData[static_cast<UnderlyingType>(n)]; }
+    reference operator[](E n)
+    {
+        ASSERT(static_cast<size_t>(n) < mPrivateData.size());
+        return mPrivateData[static_cast<UnderlyingType>(n)];
+    }
+
+    const_reference operator[](E n) const
+    {
+        ASSERT(static_cast<size_t>(n) < mPrivateData.size());
+        return mPrivateData[static_cast<UnderlyingType>(n)];
+    }
+
     const_reference at(E n) const { return mPrivateData.at(static_cast<UnderlyingType>(n)); }
     reference at(E n) { return mPrivateData.at(static_cast<UnderlyingType>(n)); }
 
diff --git a/src/libANGLE/Context.cpp b/src/libANGLE/Context.cpp
index fad487167..315045259 100644
--- a/src/libANGLE/Context.cpp
+++ b/src/libANGLE/Context.cpp
@@ -361,7 +361,6 @@ Context::Context(rx::EGLImplFactory *implFactory,
       mWebGLContext(GetWebGLContext(attribs)),
       mExtensionsEnabled(GetExtensionsEnabled(attribs, mWebGLContext)),
       mMemoryProgramCache(memoryProgramCache),
-      mStateCache(this),
       mVertexArrayObserverBinding(this, kVertexArraySubjectIndex),
       mDrawFramebufferObserverBinding(this, kDrawFramebufferSubjectIndex),
       mReadFramebufferObserverBinding(this, kReadFramebufferSubjectIndex),
@@ -3430,6 +3429,9 @@ void Context::updateCaps()
     }
 
     mThreadPool = angle::WorkerThreadPool::Create(mExtensions.parallelShaderCompile);
+
+    // Reinitialize state cache after extension changes.
+    mStateCache.initialize(this);
 }
 
 void Context::initWorkarounds()
@@ -7987,17 +7989,22 @@ GLenum ErrorSet::popError()
 }
 
 // StateCache implementation.
-StateCache::StateCache(Context *context)
+StateCache::StateCache()
     : mCachedHasAnyEnabledClientAttrib(false),
       mCachedNonInstancedVertexElementLimit(0),
       mCachedInstancedVertexElementLimit(0),
       mCachedBasicDrawStatesError(kInvalidPointer)
 {
-    updateValidDrawModes(context);
 }
 
 StateCache::~StateCache() = default;
 
+void StateCache::initialize(Context *context)
+{
+    updateValidDrawModes(context);
+    updateValidBindTextureTypes(context);
+}
+
 void StateCache::updateActiveAttribsMask(Context *context)
 {
     bool isGLES1         = context->isGLES1();
@@ -8209,4 +8216,24 @@ void StateCache::updateValidDrawModes(Context *context)
         }};
     }
 }
+
+void StateCache::updateValidBindTextureTypes(Context *context)
+{
+    const Extensions &exts = context->getExtensions();
+    bool isGLES3           = context->getClientMajorVersion() >= 3;
+    bool isGLES31          = context->getClientVersion() >= Version(3, 1);
+
+    mCachedValidBindTextureTypes = {{
+        true,                                                    /* _2D */
+        isGLES3,                                                 /* _2DArray */
+        isGLES31,                                                /* _2DMultisample */
+        exts.textureStorageMultisample2DArray,                   /* _2DMultisampleArray */
+        isGLES3,                                                 /* _3D */
+        exts.eglImageExternal || exts.eglStreamConsumerExternal, /* External */
+        exts.textureRectangle,                                   /* Rectangle */
+        true,                                                    /* CubeMap */
+        false,                                                   /* InvalidEnum */
+
+    }};
+}
 }  // namespace gl
diff --git a/src/libANGLE/Context.h b/src/libANGLE/Context.h
index 24523774d..29cf776cb 100644
--- a/src/libANGLE/Context.h
+++ b/src/libANGLE/Context.h
@@ -92,9 +92,11 @@ class ErrorSet : angle::NonCopyable
 class StateCache final : angle::NonCopyable
 {
   public:
-    StateCache(Context *context);
+    StateCache();
     ~StateCache();
 
+    void initialize(Context *context);
+
     // Places that can trigger updateActiveAttribsMask:
     // 1. onVertexArrayBindingChange.
     // 2. onProgramExecutableChange.
@@ -150,6 +152,12 @@ class StateCache final : angle::NonCopyable
         return mCachedValidDrawModes[primitiveMode];
     }
 
+    // Cannot change except on Context/Extension init.
+    bool isValidBindTextureType(TextureType type) const
+    {
+        return mCachedValidBindTextureTypes[type];
+    }
+
     // State change notifications.
     void onVertexArrayBindingChange(Context *context);
     void onProgramExecutableChange(Context *context);
@@ -174,6 +182,7 @@ class StateCache final : angle::NonCopyable
     void updateVertexElementLimits(Context *context);
     void updateBasicDrawStatesError();
     void updateValidDrawModes(Context *context);
+    void updateValidBindTextureTypes(Context *context);
 
     intptr_t getBasicDrawStatesErrorImpl(Context *context) const;
 
@@ -187,9 +196,11 @@ class StateCache final : angle::NonCopyable
     GLint64 mCachedInstancedVertexElementLimit;
     mutable intptr_t mCachedBasicDrawStatesError;
 
-    // Reserve an extra slot at the end of the map for invalid enum.
+    // Reserve an extra slot at the end of these maps for invalid enum.
     angle::PackedEnumMap<PrimitiveMode, bool, angle::EnumSize<PrimitiveMode>() + 1>
         mCachedValidDrawModes;
+    angle::PackedEnumMap<TextureType, bool, angle::EnumSize<TextureType>() + 1>
+        mCachedValidBindTextureTypes;
 };
 
 class Context final : public egl::LabeledObject, angle::NonCopyable, public angle::ObserverInterface
diff --git a/src/libANGLE/validationES2.cpp b/src/libANGLE/validationES2.cpp
index 5433c43e5..15730176c 100644
--- a/src/libANGLE/validationES2.cpp
+++ b/src/libANGLE/validationES2.cpp
@@ -1110,6 +1110,44 @@ bool ValidDstBlendFunc(const Context *context, GLenum val)
     return false;
 }
 
+void RecordBindTextureTypeError(Context *context, TextureType target)
+{
+    ASSERT(!context->getStateCache().isValidBindTextureType(target));
+
+    switch (target)
+    {
+        case TextureType::Rectangle:
+            ASSERT(!context->getExtensions().textureRectangle);
+            context->handleError(InvalidEnum()
+                                 << "Context does not support GL_ANGLE_texture_rectangle");
+            break;
+
+        case TextureType::_3D:
+        case TextureType::_2DArray:
+            ASSERT(context->getClientMajorVersion() < 3);
+            ANGLE_VALIDATION_ERR(context, InvalidEnum(), ES3Required);
+            break;
+
+        case TextureType::_2DMultisample:
+            ASSERT(context->getClientVersion() < Version(3, 1));
+            ANGLE_VALIDATION_ERR(context, InvalidEnum(), ES31Required);
+            break;
+
+        case TextureType::_2DMultisampleArray:
+            ASSERT(!context->getExtensions().textureStorageMultisample2DArray);
+            ANGLE_VALIDATION_ERR(context, InvalidEnum(), MultisampleArrayExtensionRequired);
+            break;
+
+        case TextureType::External:
+            ASSERT(!context->getExtensions().eglImageExternal &&
+                   !context->getExtensions().eglStreamConsumerExternal);
+            context->handleError(InvalidEnum() << "External texture extension not enabled");
+            break;
+
+        default:
+            ANGLE_VALIDATION_ERR(context, InvalidEnum(), InvalidTextureTarget);
+    }
+}
 }  // anonymous namespace
 
 bool ValidateES2TexImageParameters(Context *context,
@@ -3044,55 +3082,10 @@ bool ValidateFlushMappedBufferRangeEXT(Context *context,
 
 bool ValidateBindTexture(Context *context, TextureType target, GLuint texture)
 {
-    switch (target)
+    if (!context->getStateCache().isValidBindTextureType(target))
     {
-        case TextureType::_2D:
-        case TextureType::CubeMap:
-            break;
-
-        case TextureType::Rectangle:
-            if (!context->getExtensions().textureRectangle)
-            {
-                context->handleError(InvalidEnum()
-                                     << "Context does not support GL_ANGLE_texture_rectangle");
-                return false;
-            }
-            break;
-
-        case TextureType::_3D:
-        case TextureType::_2DArray:
-            if (context->getClientMajorVersion() < 3)
-            {
-                ANGLE_VALIDATION_ERR(context, InvalidEnum(), ES3Required);
-                return false;
-            }
-            break;
-
-        case TextureType::_2DMultisample:
-            if (context->getClientVersion() < Version(3, 1))
-            {
-                ANGLE_VALIDATION_ERR(context, InvalidEnum(), ES31Required);
-                return false;
-            }
-            break;
-        case TextureType::_2DMultisampleArray:
-            if (!context->getExtensions().textureStorageMultisample2DArray)
-            {
-                ANGLE_VALIDATION_ERR(context, InvalidEnum(), MultisampleArrayExtensionRequired);
-                return false;
-            }
-            break;
-        case TextureType::External:
-            if (!context->getExtensions().eglImageExternal &&
-                !context->getExtensions().eglStreamConsumerExternal)
-            {
-                context->handleError(InvalidEnum() << "External texture extension not enabled");
-                return false;
-            }
-            break;
-        default:
-            ANGLE_VALIDATION_ERR(context, InvalidEnum(), InvalidTextureTarget);
-            return false;
+        RecordBindTextureTypeError(context, target);
+        return false;
     }
 
     if (texture == 0)