diff --git a/dlls/jscript/engine.c b/dlls/jscript/engine.c
index c74aa75a744..15f71bd3f50 100644
--- a/dlls/jscript/engine.c
+++ b/dlls/jscript/engine.c
@@ -295,7 +295,7 @@ void scope_release(scope_chain_t *scope)
     heap_free(scope);
 }
 
-HRESULT create_exec_ctx(script_ctx_t *script_ctx, IDispatch *this_obj, jsdisp_t *var_disp,
+HRESULT create_exec_ctx(script_ctx_t *script_ctx, jsdisp_t *var_disp,
         BOOL is_global, exec_ctx_t **ret)
 {
     exec_ctx_t *ctx;
@@ -308,26 +308,6 @@ HRESULT create_exec_ctx(script_ctx_t *script_ctx, IDispatch *this_obj, jsdisp_t
     ctx->is_global = is_global;
     ctx->ret = jsval_undefined();
 
-    /* ECMA-262 3rd Edition    11.2.3.7 */
-    if(this_obj) {
-        jsdisp_t *jsthis;
-
-        jsthis = iface_to_jsdisp((IUnknown*)this_obj);
-        if(jsthis) {
-            if(jsthis->builtin_info->class == JSCLASS_GLOBAL || jsthis->builtin_info->class == JSCLASS_NONE)
-                this_obj = NULL;
-            jsdisp_release(jsthis);
-        }
-    }
-
-    if(this_obj)
-        ctx->this_obj = this_obj;
-    else if(script_ctx->host_global)
-        ctx->this_obj = script_ctx->host_global;
-    else
-        ctx->this_obj = to_disp(script_ctx->global);
-    IDispatch_AddRef(ctx->this_obj);
-
     jsdisp_addref(var_disp);
     ctx->var_disp = var_disp;
 
@@ -345,8 +325,6 @@ void exec_release(exec_ctx_t *ctx)
 
     if(ctx->var_disp)
         jsdisp_release(ctx->var_disp);
-    if(ctx->this_obj)
-        IDispatch_Release(ctx->this_obj);
     if(ctx->script)
         script_release(ctx->script);
     jsval_release(ctx->ret);
@@ -1067,13 +1045,12 @@ static HRESULT interp_call_member(script_ctx_t *ctx)
 /* ECMA-262 3rd Edition    11.1.1 */
 static HRESULT interp_this(script_ctx_t *ctx)
 {
-    IDispatch *this_obj;
+    call_frame_t *frame = ctx->call_ctx;
 
     TRACE("\n");
 
-    this_obj = ctx->call_ctx->exec_ctx->this_obj;
-    IDispatch_AddRef(this_obj);
-    return stack_push(ctx, jsval_disp(this_obj));
+    IDispatch_AddRef(frame->this_obj);
+    return stack_push(ctx, jsval_disp(frame->this_obj));
 }
 
 /* ECMA-262 3rd Edition    10.1.4 */
@@ -2413,6 +2390,8 @@ OP_LIST
 
 static void release_call_frame(call_frame_t *frame)
 {
+    if(frame->this_obj)
+        IDispatch_Release(frame->this_obj);
     if(frame->scope)
         scope_release(frame->scope);
     heap_free(frame);
@@ -2556,10 +2535,23 @@ static HRESULT bind_event_target(script_ctx_t *ctx, function_code_t *func, jsdis
     return hres;
 }
 
-static HRESULT setup_call_frame(exec_ctx_t *ctx, bytecode_t *bytecode, function_code_t *function, scope_chain_t *scope)
+static HRESULT setup_call_frame(exec_ctx_t *ctx, bytecode_t *bytecode, function_code_t *function, scope_chain_t *scope,
+        IDispatch *this_obj)
 {
     call_frame_t *frame;
 
+    /* ECMA-262 3rd Edition    11.2.3.7 */
+    if(this_obj) {
+        jsdisp_t *jsthis;
+
+        jsthis = iface_to_jsdisp((IUnknown*)this_obj);
+        if(jsthis) {
+            if(jsthis->builtin_info->class == JSCLASS_GLOBAL || jsthis->builtin_info->class == JSCLASS_NONE)
+                this_obj = NULL;
+            jsdisp_release(jsthis);
+        }
+    }
+
     frame = heap_alloc_zero(sizeof(*frame));
     if(!frame)
         return E_OUTOFMEMORY;
@@ -2572,6 +2564,14 @@ static HRESULT setup_call_frame(exec_ctx_t *ctx, bytecode_t *bytecode, function_
     if(scope)
         frame->base_scope = frame->scope = scope_addref(scope);
 
+    if(this_obj)
+        frame->this_obj = this_obj;
+    else if(ctx->script->host_global)
+        frame->this_obj = ctx->script->host_global;
+    else
+        frame->this_obj = to_disp(ctx->script->global);
+    IDispatch_AddRef(frame->this_obj);
+
     frame->exec_ctx = ctx;
 
     frame->prev_frame = ctx->script->call_ctx;
@@ -2579,7 +2579,8 @@ static HRESULT setup_call_frame(exec_ctx_t *ctx, bytecode_t *bytecode, function_
     return S_OK;
 }
 
-HRESULT exec_source(exec_ctx_t *ctx, bytecode_t *code, function_code_t *func, scope_chain_t *scope, jsval_t *ret)
+HRESULT exec_source(exec_ctx_t *ctx, bytecode_t *code, function_code_t *func, scope_chain_t *scope,
+        IDispatch *this_obj, jsval_t *ret)
 {
     jsval_t val;
     unsigned i;
@@ -2614,7 +2615,7 @@ HRESULT exec_source(exec_ctx_t *ctx, bytecode_t *code, function_code_t *func, sc
         }
     }
 
-    hres = setup_call_frame(ctx, code, func, scope);
+    hres = setup_call_frame(ctx, code, func, scope, this_obj);
     if(FAILED(hres))
         return hres;
 
diff --git a/dlls/jscript/engine.h b/dlls/jscript/engine.h
index 6c738ebe888..cd4051f26be 100644
--- a/dlls/jscript/engine.h
+++ b/dlls/jscript/engine.h
@@ -198,6 +198,8 @@ typedef struct _call_frame_t {
     scope_chain_t *scope;
     scope_chain_t *base_scope;
 
+    IDispatch *this_obj;
+
     bytecode_t *bytecode;
     function_code_t *function;
 
@@ -210,7 +212,6 @@ struct _exec_ctx_t {
 
     script_ctx_t *script;
     jsdisp_t *var_disp;
-    IDispatch *this_obj;
     BOOL is_global;
 
     jsval_t ret;
@@ -222,6 +223,6 @@ static inline void exec_addref(exec_ctx_t *ctx)
 }
 
 void exec_release(exec_ctx_t*) DECLSPEC_HIDDEN;
-HRESULT create_exec_ctx(script_ctx_t*,IDispatch*,jsdisp_t*,BOOL,exec_ctx_t**) DECLSPEC_HIDDEN;
-HRESULT exec_source(exec_ctx_t*,bytecode_t*,function_code_t*,scope_chain_t*,jsval_t*) DECLSPEC_HIDDEN;
+HRESULT create_exec_ctx(script_ctx_t*,jsdisp_t*,BOOL,exec_ctx_t**) DECLSPEC_HIDDEN;
+HRESULT exec_source(exec_ctx_t*,bytecode_t*,function_code_t*,scope_chain_t*,IDispatch*,jsval_t*) DECLSPEC_HIDDEN;
 HRESULT create_source_function(script_ctx_t*,bytecode_t*,function_code_t*,scope_chain_t*,jsdisp_t**) DECLSPEC_HIDDEN;
diff --git a/dlls/jscript/function.c b/dlls/jscript/function.c
index 2c378b3fb84..05792bd29d0 100644
--- a/dlls/jscript/function.c
+++ b/dlls/jscript/function.c
@@ -239,13 +239,13 @@ static HRESULT invoke_source(script_ctx_t *ctx, FunctionInstance *function, IDis
 
     hres = scope_push(function->scope_chain, var_disp, to_disp(var_disp), &scope);
     if(SUCCEEDED(hres)) {
-        hres = create_exec_ctx(ctx, this_obj, var_disp, FALSE, &exec_ctx);
+        hres = create_exec_ctx(ctx, var_disp, FALSE, &exec_ctx);
         if(SUCCEEDED(hres)) {
             jsdisp_t *prev_args;
 
             prev_args = function->arguments;
             function->arguments = arg_disp;
-            hres = exec_source(exec_ctx, function->code, function->func_code, scope, r);
+            hres = exec_source(exec_ctx, function->code, function->func_code, scope, this_obj, r);
             function->arguments = prev_args;
 
             exec_release(exec_ctx);
diff --git a/dlls/jscript/global.c b/dlls/jscript/global.c
index ec3e355e42a..5574f504f5e 100644
--- a/dlls/jscript/global.c
+++ b/dlls/jscript/global.c
@@ -223,7 +223,7 @@ static HRESULT JSGlobal_eval(script_ctx_t *ctx, vdisp_t *jsthis, WORD flags, uns
         return throw_syntax_error(ctx, hres, NULL);
     }
 
-    hres = exec_source(ctx->call_ctx->exec_ctx, code, &code->global_code, frame->scope, r);
+    hres = exec_source(ctx->call_ctx->exec_ctx, code, &code->global_code, frame->scope, frame->this_obj, r);
     release_bytecode(code);
     return hres;
 }
diff --git a/dlls/jscript/jscript.c b/dlls/jscript/jscript.c
index c5c7705ee74..3dda22c17f1 100644
--- a/dlls/jscript/jscript.c
+++ b/dlls/jscript/jscript.c
@@ -105,14 +105,14 @@ static HRESULT exec_global_code(JScript *This, bytecode_t *code)
     exec_ctx_t *exec_ctx;
     HRESULT hres;
 
-    hres = create_exec_ctx(This->ctx, NULL, This->ctx->global, TRUE, &exec_ctx);
+    hres = create_exec_ctx(This->ctx, This->ctx->global, TRUE, &exec_ctx);
     if(FAILED(hres))
         return hres;
 
     IActiveScriptSite_OnEnterScript(This->site);
 
     clear_ei(This->ctx);
-    hres = exec_source(exec_ctx, code, &code->global_code, NULL, NULL);
+    hres = exec_source(exec_ctx, code, &code->global_code, NULL, NULL, NULL);
     exec_release(exec_ctx);
 
     IActiveScriptSite_OnLeaveScript(This->site);
@@ -776,14 +776,14 @@ static HRESULT WINAPI JScriptParse_ParseScriptText(IActiveScriptParse *iface,
     if(dwFlags & SCRIPTTEXT_ISEXPRESSION) {
         exec_ctx_t *exec_ctx;
 
-        hres = create_exec_ctx(This->ctx, NULL, This->ctx->global, TRUE, &exec_ctx);
+        hres = create_exec_ctx(This->ctx, This->ctx->global, TRUE, &exec_ctx);
         if(SUCCEEDED(hres)) {
             jsval_t r;
 
             IActiveScriptSite_OnEnterScript(This->site);
 
             clear_ei(This->ctx);
-            hres = exec_source(exec_ctx, code, &code->global_code, NULL, &r);
+            hres = exec_source(exec_ctx, code, &code->global_code, NULL, NULL, &r);
             if(SUCCEEDED(hres)) {
                 if(pvarResult)
                     hres = jsval_to_variant(r, pvarResult);