diff --git a/src/backend/bootstrap/bootstrap.c b/src/backend/bootstrap/bootstrap.c
index 7d4e24fa30..ef6311b075 100644
--- a/src/backend/bootstrap/bootstrap.c
+++ b/src/backend/bootstrap/bootstrap.c
@@ -202,14 +202,6 @@ AuxiliaryProcessMain(int argc, char *argv[])
 
 	MyStartTime = time(NULL);
 
-	/*
-	 * Fire up essential subsystems: error and memory management
-	 *
-	 * If we are running under the postmaster, this is done already.
-	 */
-	if (!IsUnderPostmaster)
-		MemoryContextInit();
-
 	/* Compute paths, if we didn't inherit them from postmaster */
 	if (my_exec_path[0] == '\0')
 	{
diff --git a/src/backend/main/main.c b/src/backend/main/main.c
index 4ee8a153d9..98da177de9 100644
--- a/src/backend/main/main.c
+++ b/src/backend/main/main.c
@@ -39,6 +39,7 @@
 #include "postmaster/postmaster.h"
 #include "tcop/tcopprot.h"
 #include "utils/help_config.h"
+#include "utils/memutils.h"
 #include "utils/pg_locale.h"
 #include "utils/ps_status.h"
 
@@ -85,6 +86,15 @@ main(int argc, char *argv[])
 	pgwin32_install_crashdump_handler();
 #endif
 
+	/*
+	 * Fire up essential subsystems: error and memory management
+	 *
+	 * Code after this point is allowed to use elog/ereport, though
+	 * localization of messages may not work right away, and messages won't go
+	 * anywhere but stderr until GUC settings get loaded.
+	 */
+	MemoryContextInit();
+
 	/*
 	 * Set up locale information from environment.	Note that LC_CTYPE and
 	 * LC_COLLATE will be overridden later from pg_control if we are in an
diff --git a/src/backend/postmaster/postmaster.c b/src/backend/postmaster/postmaster.c
index a7e40cc4a5..23f4ada7b9 100644
--- a/src/backend/postmaster/postmaster.c
+++ b/src/backend/postmaster/postmaster.c
@@ -560,11 +560,6 @@ PostmasterMain(int argc, char *argv[])
 	 */
 	umask(S_IRWXG | S_IRWXO);
 
-	/*
-	 * Fire up essential subsystems: memory management
-	 */
-	MemoryContextInit();
-
 	/*
 	 * By default, palloc() requests in the postmaster will be allocated in
 	 * the PostmasterContext, which is space that can be recycled by backends.
@@ -4468,7 +4463,6 @@ SubPostmasterMain(int argc, char *argv[])
 	whereToSendOutput = DestNone;
 
 	/* Setup essential subsystems (to ensure elog() behaves sanely) */
-	MemoryContextInit();
 	InitializeGUCOptions();
 
 	/* Read in the variables file */
diff --git a/src/backend/tcop/postgres.c b/src/backend/tcop/postgres.c
index dcd8cdf3c1..b7612b9b5f 100644
--- a/src/backend/tcop/postgres.c
+++ b/src/backend/tcop/postgres.c
@@ -3548,14 +3548,6 @@ PostgresMain(int argc, char *argv[],
 		MyStartTime = time(NULL);
 	}
 
-	/*
-	 * Fire up essential subsystems: error and memory management
-	 *
-	 * If we are running under the postmaster, this is done already.
-	 */
-	if (!IsUnderPostmaster)
-		MemoryContextInit();
-
 	SetProcessingMode(InitProcessing);
 
 	/* Compute paths, if we didn't inherit them from postmaster */
diff --git a/src/backend/utils/error/elog.c b/src/backend/utils/error/elog.c
index 3de162b9d5..8705586d56 100644
--- a/src/backend/utils/error/elog.c
+++ b/src/backend/utils/error/elog.c
@@ -310,6 +310,18 @@ errstart(int elevel, const char *filename, int lineno,
 	if (elevel < ERROR && !output_to_server && !output_to_client)
 		return false;
 
+	/*
+	 * We need to do some actual work.  Make sure that memory context
+	 * initialization has finished, else we can't do anything useful.
+	 */
+	if (ErrorContext == NULL)
+	{
+		/* Ooops, hard crash time; very little we can do safely here */
+		write_stderr("error occurred at %s:%d before error message processing is available\n",
+					 filename ? filename : "(unknown file)", lineno);
+		exit(2);
+	}
+
 	/*
 	 * Okay, crank up a stack entry to store the info in.
 	 */
@@ -1238,6 +1250,15 @@ elog_start(const char *filename, int lineno, const char *funcname)
 {
 	ErrorData  *edata;
 
+	/* Make sure that memory context initialization has finished */
+	if (ErrorContext == NULL)
+	{
+		/* Ooops, hard crash time; very little we can do safely here */
+		write_stderr("error occurred at %s:%d before error message processing is available\n",
+					 filename ? filename : "(unknown file)", lineno);
+		exit(2);
+	}
+
 	if (++errordata_stack_depth >= ERRORDATA_STACK_SIZE)
 	{
 		/*
diff --git a/src/backend/utils/mmgr/mcxt.c b/src/backend/utils/mmgr/mcxt.c
index b60ca90d0a..7b089f77df 100644
--- a/src/backend/utils/mmgr/mcxt.c
+++ b/src/backend/utils/mmgr/mcxt.c
@@ -72,7 +72,8 @@ static void MemoryContextStatsInternal(MemoryContext context, int level);
  * In normal multi-backend operation, this is called once during
  * postmaster startup, and not at all by individual backend startup
  * (since the backends inherit an already-initialized context subsystem
- * by virtue of being forked off the postmaster).
+ * by virtue of being forked off the postmaster).  But in an EXEC_BACKEND
+ * build, each process must do this for itself.
  *
  * In a standalone backend this must be called during backend startup.
  */
@@ -106,6 +107,9 @@ MemoryContextInit(void)
 	 * where retained memory in a context is *essential* --- we want to be
 	 * sure ErrorContext still has some memory even if we've run out
 	 * elsewhere!
+	 *
+	 * This should be the last step in this function, as elog.c assumes memory
+	 * management works once ErrorContext is non-null.
 	 */
 	ErrorContext = AllocSetContextCreate(TopMemoryContext,
 										 "ErrorContext",