diff --git a/contrib/auto_explain/auto_explain.c b/contrib/auto_explain/auto_explain.c
index 4ccd2aa..192a3a1 100644
--- a/contrib/auto_explain/auto_explain.c
+++ b/contrib/auto_explain/auto_explain.c
@@ -14,8 +14,13 @@
 
 #include <limits.h>
 
+#include "access/parallel.h"
 #include "commands/explain.h"
 #include "executor/instrument.h"
+#include "miscadmin.h"
+#include "storage/ipc.h"
+#include "storage/lwlock.h"
+#include "storage/shmem.h"
 #include "utils/guc.h"
 
 PG_MODULE_MAGIC;
@@ -47,10 +52,13 @@ static ExecutorStart_hook_type prev_ExecutorStart = NULL;
 static ExecutorRun_hook_type prev_ExecutorRun = NULL;
 static ExecutorFinish_hook_type prev_ExecutorFinish = NULL;
 static ExecutorEnd_hook_type prev_ExecutorEnd = NULL;
+static shmem_startup_hook_type prev_shmem_startup_hook = NULL;
 
 /* Is the current query sampled, per backend */
 static bool current_query_sampled = true;
 
+static int parent;
+
 #define auto_explain_enabled() \
 	(auto_explain_log_min_duration >= 0 && \
 	 (nesting_level == 0 || auto_explain_log_nested_statements))
@@ -65,6 +73,18 @@ static void explain_ExecutorRun(QueryDesc *queryDesc,
 static void explain_ExecutorFinish(QueryDesc *queryDesc);
 static void explain_ExecutorEnd(QueryDesc *queryDesc);
 
+typedef struct AutoExplainState
+{
+	LWLock	   *lock;							/* protects shared statr */
+	bool		sampled[FLEXIBLE_ARRAY_MEMBER];	/* should we sample this query? */
+} AutoExplainState;
+
+static AutoExplainState *explainState;
+
+static void explain_shmem_startup(void);
+static bool is_query_sampled(void);
+static void set_query_sampled(bool sample);
+static Size explain_shmem_size(void);
 
 /*
  * Module load callback
@@ -72,6 +92,9 @@ static void explain_ExecutorEnd(QueryDesc *queryDesc);
 void
 _PG_init(void)
 {
+	if (!process_shared_preload_libraries_in_progress)
+		elog(ERROR, "auto_explain can only be loaded via shared_preload_libraries");
+
 	/* Define custom GUC variables. */
 	DefineCustomIntVariable("auto_explain.log_min_duration",
 		 "Sets the minimum execution time above which plans will be logged.",
@@ -176,6 +199,8 @@ _PG_init(void)
 							 NULL,
 							 NULL);
 
+	RequestAddinShmemSpace(explain_shmem_size());
+	RequestNamedLWLockTranche("auto_explain", 1);
 	EmitWarningsOnPlaceholders("auto_explain");
 
 	/* Install hooks. */
@@ -187,6 +212,15 @@ _PG_init(void)
 	ExecutorFinish_hook = explain_ExecutorFinish;
 	prev_ExecutorEnd = ExecutorEnd_hook;
 	ExecutorEnd_hook = explain_ExecutorEnd;
+
+	prev_shmem_startup_hook = shmem_startup_hook;
+	shmem_startup_hook = explain_shmem_startup;
+}
+
+static Size
+explain_shmem_size(void)
+{
+	return offsetof(AutoExplainState, sampled) + MaxConnections * sizeof(bool);
 }
 
 /*
@@ -200,6 +234,7 @@ _PG_fini(void)
 	ExecutorRun_hook = prev_ExecutorRun;
 	ExecutorFinish_hook = prev_ExecutorFinish;
 	ExecutorEnd_hook = prev_ExecutorEnd;
+	shmem_startup_hook = prev_shmem_startup_hook;
 }
 
 /*
@@ -208,15 +243,20 @@ _PG_fini(void)
 static void
 explain_ExecutorStart(QueryDesc *queryDesc, int eflags)
 {
+	parent = MyBackendId;
+
 	/*
 	 * For rate sampling, randomly choose top-level statement. Either all
 	 * nested statements will be explained or none will.
 	 */
-	if (auto_explain_log_min_duration >= 0 && nesting_level == 0)
+	if (auto_explain_log_min_duration >= 0 && nesting_level == 0 && (! IsParallelWorker()))
+	{
 		current_query_sampled = (random() < auto_explain_sample_rate *
 								 MAX_RANDOM_VALUE);
+		set_query_sampled(current_query_sampled);
+	}
 
-	if (auto_explain_enabled() && current_query_sampled)
+	if (auto_explain_enabled() && is_query_sampled())
 	{
 		/* Enable per-node instrumentation iff log_analyze is required. */
 		if (auto_explain_log_analyze && (eflags & EXEC_FLAG_EXPLAIN_ONLY) == 0)
@@ -235,7 +275,7 @@ explain_ExecutorStart(QueryDesc *queryDesc, int eflags)
 	else
 		standard_ExecutorStart(queryDesc, eflags);
 
-	if (auto_explain_enabled() && current_query_sampled)
+	if (auto_explain_enabled() && is_query_sampled())
 	{
 		/*
 		 * Set up to track total elapsed time in ExecutorRun.  Make sure the
@@ -305,7 +345,7 @@ explain_ExecutorFinish(QueryDesc *queryDesc)
 static void
 explain_ExecutorEnd(QueryDesc *queryDesc)
 {
-	if (queryDesc->totaltime && auto_explain_enabled() && current_query_sampled)
+	if (queryDesc->totaltime && auto_explain_enabled() && (! IsParallelWorker()))
 	{
 		double		msec;
 
@@ -366,3 +406,57 @@ explain_ExecutorEnd(QueryDesc *queryDesc)
 	else
 		standard_ExecutorEnd(queryDesc);
 }
+
+static void
+explain_shmem_startup(void)
+{
+	bool		found;
+
+	if (prev_shmem_startup_hook)
+		prev_shmem_startup_hook();
+
+	explainState = NULL;
+
+	LWLockAcquire(AddinShmemInitLock, LW_EXCLUSIVE);
+
+	explainState = ShmemInitStruct("auto_explain",
+						   sizeof(AutoExplainState),
+						   &found);
+	if (!found)
+	{
+		/* First time through ... */
+		explainState->lock = &(GetNamedLWLockTranche("auto_explain"))->lock;
+		memset(explainState->sampled, 1, sizeof(bool) * MaxConnections);
+	}
+
+	LWLockRelease(AddinShmemInitLock);
+}
+
+static bool
+is_query_sampled(void)
+{
+	bool sampled;
+
+	/* in leader we can just check the global variable */
+	if (! IsParallelWorker())
+		return current_query_sampled;
+
+	/* in worker processes we need to get the info from shared memory */
+	LWLockAcquire(explainState->lock, LW_SHARED);
+	sampled = explainState->sampled[ParallelMasterBackendId];
+	LWLockRelease(explainState->lock);
+
+	return sampled;
+}
+
+static void
+set_query_sampled(bool sample)
+{
+	/* the decisions should only be made in leader */
+	Assert(! IsParallelWorker());
+
+	/* in worker processes we need to get the info from shared memory */
+	LWLockAcquire(explainState->lock, LW_EXCLUSIVE);
+	explainState->sampled[MyBackendId] = sample;
+	LWLockRelease(explainState->lock);
+}