diff --git a/mail/mozilla-thunderbird/Makefile b/mail/mozilla-thunderbird/Makefile
index d9f44b960dd..aeaf4d9b546 100644
--- a/mail/mozilla-thunderbird/Makefile
+++ b/mail/mozilla-thunderbird/Makefile
@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.295 2019/09/13 15:05:17 landry Exp $
+# $OpenBSD: Makefile,v 1.296 2019/09/22 17:19:07 sthen Exp $
 
 ONLY_FOR_ARCHS =	amd64 i386
 COMMENT-main =		Mozilla e-mail, rss and usenet client
@@ -87,11 +87,6 @@ GNU_ARCH =	${MACHINE_ARCH:S/amd64/x86_64/}
 GUIDS =	gdata-provider {a62ef8ec-5fdc-40c2-873c-223b8a6925cc} #\
 #	lightning {e2fda1a4-762b-4020-b5ad-a41df1933103}
 
-CONFIGURE_ARGS +=	--disable-debug-symbols		#maybe also needed
-.if ${MACHINE_ARCH} == "i386"
-DPB_PROPERTIES +=	lonesome
-.endif
-
 EXTDIR =	${PREFIX}/lib/${MOZILLA_PROJECT}/distribution/extensions/
 
 post-install:
diff --git a/www/firefox-esr/Makefile b/www/firefox-esr/Makefile
index d3679ec9707..1778ea831b3 100644
--- a/www/firefox-esr/Makefile
+++ b/www/firefox-esr/Makefile
@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.105 2019/09/19 19:15:55 landry Exp $
+# $OpenBSD: Makefile,v 1.106 2019/09/22 17:19:06 sthen Exp $
 
 COMMENT =	Firefox web browser, Extended Support Release
 ONLY_FOR_ARCHS =	amd64 i386
@@ -62,11 +62,6 @@ CONFIGURE_ARGS +=	--prefix=${PREFIX}
 CONFIGURE_ARGS +=	--with-app-name=firefox-esr
 
 CONFIGURE_ARGS +=	--enable-release #1386371
-.if ${MACHINE_ARCH} == "i386"
-CONFIGURE_ARGS +=	--disable-debug-symbols
-MAKE_ENV +=		RUSTFLAGS="-C target-cpu=pentium4 --cfg target_feature=\"sse2\""
-DPB_PROPERTIES =	lonesome
-.endif
 CONFIGURE_ARGS +=	--enable-sandbox --enable-content-sandbox
 CONFIGURE_ARGS +=	--with-libclang-path=${LOCALBASE}/lib
 CONFIGURE_ARGS +=	--with-clang-path=${LOCALBASE}/bin/clang
diff --git a/www/mozilla-firefox/Makefile b/www/mozilla-firefox/Makefile
index 3c580854139..fd57f4d6999 100644
--- a/www/mozilla-firefox/Makefile
+++ b/www/mozilla-firefox/Makefile
@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.394 2019/09/18 16:58:05 landry Exp $
+# $OpenBSD: Makefile,v 1.395 2019/09/22 17:19:06 sthen Exp $
 
 COMMENT =	Mozilla web browser
 ONLY_FOR_ARCHS =	amd64 i386 aarch64
@@ -62,12 +62,6 @@ CONFIGURE_ARGS +=	--prefix=${PREFIX}
 MAKE_ENV +=		BUILD_VERBOSE_LOG="1"
 
 CONFIGURE_ARGS +=	--enable-release #1386371
-.if ${MACHINE_ARCH} == "i386"
-CONFIGURE_ARGS +=	--disable-debug-symbols
-MAKE_ENV +=		RUSTFLAGS="-C target-cpu=pentium4 --cfg target_feature=\"sse2\""
-# override parallel
-DPB_PROPERTIES =	lonesome
-.endif
 CONFIGURE_ARGS +=	--enable-sandbox
 CONFIGURE_ARGS +=	--with-libclang-path=${LOCALBASE}/lib
 SUBST_VARS +=	LOCALBASE X11BASE
diff --git a/www/mozilla/mozilla.port.mk b/www/mozilla/mozilla.port.mk
index f086ef17716..a3c53b77068 100644
--- a/www/mozilla/mozilla.port.mk
+++ b/www/mozilla/mozilla.port.mk
@@ -1,4 +1,4 @@
-# $OpenBSD: mozilla.port.mk,v 1.126 2019/09/03 16:25:03 landry Exp $
+# $OpenBSD: mozilla.port.mk,v 1.127 2019/09/22 17:19:06 sthen Exp $
 
 # ppc: firefox-esr/thunderbird xpcshell segfaults during startup compilation
 # ppc: seamonkey/firefox - failure to link for atomic ops on 64 bits
@@ -8,7 +8,14 @@
 # seamonkey-2.22/comm-release/mozilla/js/src/vm/Interpreter.cpp:743
 # firefox-25.0/mozilla-release/js/src/builtin/MapObject.cpp:1119
 
+.if ${MACHINE_ARCH} == "i386"
+MAKE_ENV +=		RUSTFLAGS="-C target-cpu=pentium4 --cfg target_feature=\"sse2\""
+# reduce build memory usage:
+CONFIGURE_ARGS +=	--disable-debug-symbols
+DPB_PROPERTIES +=	lonesome
+.else
 DPB_PROPERTIES +=	parallel
+.endif
 
 .for _lib in ${MOZILLA_LIBS}
 SHARED_LIBS +=	${_lib}	${SO_VERSION}
diff --git a/www/seamonkey/Makefile b/www/seamonkey/Makefile
index 04a9e27505a..1904cb7f0c0 100644
--- a/www/seamonkey/Makefile
+++ b/www/seamonkey/Makefile
@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.231 2019/09/03 16:25:31 landry Exp $
+# $OpenBSD: Makefile,v 1.232 2019/09/22 17:19:07 sthen Exp $
 
 COMMENT-main =		Mozilla application suite
 COMMENT-lightning =	Mozilla Seamonkey calendar extension
@@ -56,12 +56,6 @@ CONFIGURE_ARGS +=	--enable-calendar
 # SQLITE_CFLAGS is set from pkgconfig, but it's not used for all files that need it
 CONFIGURE_ENV =		CPPFLAGS="-I${LOCALBASE}/include"
 
-.if ${MACHINE_ARCH} == "i386"
-CONFIGURE_ARGS +=	--disable-debug-symbols
-# override parallel
-DPB_PROPERTIES =	lonesome
-.endif
-
 post-install:
 	${INSTALL_MAN} ${WRKBUILD}/dist/man/man1/seamonkey.1 ${PREFIX}/man/man1/
 
diff --git a/www/tor-browser/browser/Makefile b/www/tor-browser/browser/Makefile
index 7cf1d5627e9..8db088d1ebe 100644
--- a/www/tor-browser/browser/Makefile
+++ b/www/tor-browser/browser/Makefile
@@ -1,4 +1,4 @@
-# $OpenBSD: Makefile,v 1.35 2019/07/12 20:51:06 sthen Exp $
+# $OpenBSD: Makefile,v 1.36 2019/09/22 17:19:06 sthen Exp $
 # Some of this comes from www/firefox-esr as apropos, since Tor
 # browser is a fork of ESR.  It is a good idea to look at that
 # Makefile when editing this one (ESR versions not always the same).
@@ -80,11 +80,6 @@ CONFIGURE_ARGS +=	--enable-pie
 CONFIGURE_ARGS +=	--enable-release #1386371
 # rust-simd doesn't work with lang/rust>=1.33
 #CONFIGURE_ARGS +=	--enable-rust-simd #1261841
-.if ${MACHINE_ARCH} == "i386"
-CONFIGURE_ARGS +=	--disable-debug-symbols
-MAKE_ENV +=		RUSTFLAGS="-C target-cpu=pentium4 --cfg target_feature=\"sse2\""
-DPB_PROPERTIES =	lonesome
-.endif
 
 post-patch:
 	# hack config/baseconfig.mk to not use MOZ_APP_VERSION in a few places