diff --git a/usr.bin/make/unit-tests/directive-export-gmake.exp b/usr.bin/make/unit-tests/directive-export-gmake.exp
index cf08a0443acc..c37d3b2d8591 100644
--- a/usr.bin/make/unit-tests/directive-export-gmake.exp
+++ b/usr.bin/make/unit-tests/directive-export-gmake.exp
@@ -1,5 +1,6 @@
 make: "directive-export-gmake.mk" line 71: Invalid line 'export VAR=${:U1}', expanded to 'export VAR=1'
 make: "directive-export-gmake.mk" line 85: 16:00:00
+make: "directive-export-gmake.mk" line 92: Variable/Value missing from "export"
 make: Fatal errors encountered -- cannot continue
 make: stopped in unit-tests
 exit status 1
diff --git a/usr.bin/make/unit-tests/directive-export-gmake.mk b/usr.bin/make/unit-tests/directive-export-gmake.mk
index f7a617ab7553..6734704d3357 100644
--- a/usr.bin/make/unit-tests/directive-export-gmake.mk
+++ b/usr.bin/make/unit-tests/directive-export-gmake.mk
@@ -1,4 +1,4 @@
-# $NetBSD: directive-export-gmake.mk,v 1.7 2023/08/20 20:48:32 rillig Exp $
+# $NetBSD: directive-export-gmake.mk,v 1.8 2023/11/19 09:45:19 rillig Exp $
 #
 # Tests for the export directive (without leading dot), as in GNU make.
 
@@ -83,3 +83,24 @@ INDIRECT_TZ=	${:UAmerica/Los_Angeles}
 export TZ=${INDIRECT_TZ}
 # expect+1: 16:00:00
 .info ${%T:L:localtime=86400}
+
+
+# The '=' must be present in the unexpanded line, it cannot be generated by
+# an expression.
+EQ=	=
+# expect+1: Variable/Value missing from "export"
+export EQ_VAR${EQ}eq-value
+.if ${:!env!:MEQ_VAR=*}
+.  error
+.endif
+
+
+# The variable name must be given directly, it is not expanded.  The name of
+# the exported variable thus starts with a '$', and that name may be filtered
+# out by the platform.
+INDIRECT_NAME=	I_NAME
+INDIRECT_VALUE=	indirect value
+export ${INDIRECT_NAME}=${INDIRECT_VALUE}
+.if ${:!env!:MI_NAME=*}
+.  error
+.endif
diff --git a/usr.bin/make/unit-tests/directive-export.exp b/usr.bin/make/unit-tests/directive-export.exp
index a5d706e58f32..774a814570e3 100644
--- a/usr.bin/make/unit-tests/directive-export.exp
+++ b/usr.bin/make/unit-tests/directive-export.exp
@@ -1,4 +1,4 @@
-make: "directive-export.mk" line 50: 00:00:00
-make: "directive-export.mk" line 55: 00:00:00
-make: "directive-export.mk" line 58: 16:00:00
+make: "directive-export.mk" line 56: 00:00:00
+make: "directive-export.mk" line 61: 00:00:00
+make: "directive-export.mk" line 64: 16:00:00
 exit status 0
diff --git a/usr.bin/make/unit-tests/directive-export.mk b/usr.bin/make/unit-tests/directive-export.mk
index d46b1dc01f27..08109814bcfd 100644
--- a/usr.bin/make/unit-tests/directive-export.mk
+++ b/usr.bin/make/unit-tests/directive-export.mk
@@ -1,4 +1,4 @@
-# $NetBSD: directive-export.mk,v 1.9 2023/08/20 20:48:32 rillig Exp $
+# $NetBSD: directive-export.mk,v 1.10 2023/11/19 09:45:19 rillig Exp $
 #
 # Tests for the .export directive.
 #
@@ -35,7 +35,13 @@ VAR=		value $$ ${INDIRECT}
 .export ${:U}
 
 
-# Trigger the "This isn't going to end well" in ExportVarEnv.
+# Before a child process is started, whether for the '!=' assignment operator
+# or for the ':sh' modifier, all variables that were marked for being exported
+# are expanded and then exported.  If expanding such a variable requires
+# running a child command, the marked-as-exported variables would need to be
+# exported first, ending in an endless loop.  To avoid this endless loop,
+# don't export the variables while preparing a child process, see
+# ExportVarEnv.
 EMPTY_SHELL=	${:sh}
 .export EMPTY_SHELL	# only marked for export at this point
 _!=		:;:	# Force the variable to be actually exported.
diff --git a/usr.bin/make/var.c b/usr.bin/make/var.c
index 65728d3373a3..53a4f034b130 100644
--- a/usr.bin/make/var.c
+++ b/usr.bin/make/var.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: var.c,v 1.1069 2023/11/18 20:19:08 rillig Exp $	*/
+/*	$NetBSD: var.c,v 1.1070 2023/11/19 09:45:19 rillig Exp $	*/
 
 /*
  * Copyright (c) 1988, 1989, 1990, 1993
@@ -139,7 +139,7 @@
 #include "metachar.h"
 
 /*	"@(#)var.c	8.3 (Berkeley) 3/19/94" */
-MAKE_RCSID("$NetBSD: var.c,v 1.1069 2023/11/18 20:19:08 rillig Exp $");
+MAKE_RCSID("$NetBSD: var.c,v 1.1070 2023/11/19 09:45:19 rillig Exp $");
 
 /*
  * Variables are defined using one of the VAR=value assignments.  Their
@@ -615,13 +615,8 @@ ExportVarEnv(Var *v)
 		return true;
 	}
 
-	if (v->inUse) {
-		/*
-		 * We recursed while exporting in a child.
-		 * This isn't going to end well, just skip it.
-		 */
-		return false;
-	}
+	if (v->inUse)
+		return false;	/* see EMPTY_SHELL in directive-export.mk */
 
 	/* XXX: name is injected without escaping it */
 	expr = str_concat3("${", name, "}");