diff --git a/src/backend/executor/spi.c b/src/backend/executor/spi.c
index 33975687b38..82b6127d650 100644
--- a/src/backend/executor/spi.c
+++ b/src/backend/executor/spi.c
@@ -1584,6 +1584,7 @@ SPI_cursor_open_internal(const char *name, SPIPlanPtr plan,
 	Portal		portal;
 	SPICallbackArg spicallbackarg;
 	ErrorContextCallback spierrcontext;
+	CommandId 	this_command = InvalidCommandId;
 
 	/*
 	 * Check that the plan is something the Portal code will special-case as
@@ -1730,6 +1731,7 @@ SPI_cursor_open_internal(const char *name, SPIPlanPtr plan,
 	if (read_only)
 	{
 		ListCell   *lc;
+		this_command = GetCurrentCommandId(false);
 
 		foreach(lc, stmt_list)
 		{
@@ -1778,6 +1780,14 @@ SPI_cursor_open_internal(const char *name, SPIPlanPtr plan,
 	/* Pop the SPI stack */
 	_SPI_end_call(true);
 
+	if (read_only && this_command != GetCurrentCommandId(false))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						/* translator: %s is a SQL statement name */
+						errmsg("Damn1! Update were done in a non-volatile function")));
+	}
+
 	/* Return the created portal */
 	return portal;
 }
@@ -2404,6 +2414,7 @@ _SPI_execute_plan(SPIPlanPtr plan, const SPIExecuteOptions *options,
 	ErrorContextCallback spierrcontext;
 	CachedPlan *cplan = NULL;
 	ListCell   *lc1;
+	CommandId   this_command = InvalidCommandId;
 
 	/*
 	 * Setup error traceback support for ereport()
@@ -2473,6 +2484,11 @@ _SPI_execute_plan(SPIPlanPtr plan, const SPIExecuteOptions *options,
 				(errcode(ERRCODE_SYNTAX_ERROR),
 				 errmsg("empty query does not return tuples")));
 
+	if (options->read_only)
+	{
+		this_command = GetCurrentCommandId(false);
+	}
+
 	foreach(lc1, plan->plancache_list)
 	{
 		CachedPlanSource *plansource = (CachedPlanSource *) lfirst(lc1);
@@ -2788,6 +2804,14 @@ _SPI_execute_plan(SPIPlanPtr plan, const SPIExecuteOptions *options,
 			CommandCounterIncrement();
 	}
 
+	if (options->read_only && this_command != GetCurrentCommandId(false))
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+						/* translator: %s is a SQL statement name */
+						errmsg("Damn2! Update were done in a non-volatile function")));
+	}
+
 fail:
 
 	/* Pop the snapshot off the stack if we pushed one */