diff --git a/devel/jemalloc/Makefile b/devel/jemalloc/Makefile
index 4aceb2d134fb..101dfb64020e 100644
--- a/devel/jemalloc/Makefile
+++ b/devel/jemalloc/Makefile
@@ -1,6 +1,6 @@
-# $NetBSD: Makefile,v 1.10 2017/08/27 12:12:25 adam Exp $
+# $NetBSD: Makefile,v 1.11 2018/05/15 08:35:50 adam Exp $
 
-DISTNAME=	jemalloc-5.0.1
+DISTNAME=	jemalloc-5.1.0
 CATEGORIES=	devel
 MASTER_SITES=	${MASTER_SITE_GITHUB:=jemalloc/}
 GITHUB_RELEASE=	${PKGVERSION_NOREV}
@@ -19,7 +19,7 @@ USE_TOOLS+=		autoconf automake aclocal gmake perl:run
 GNU_CONFIGURE=		yes
 CONFIGURE_ARGS+=	--enable-cc-silence
 CONFIGURE_ARGS+=	--enable-xmalloc
-CONFIGURE_ARGS+=        --with-xslroot=${PREFIX}/share/xsl/docbook/
+CONFIGURE_ARGS+=	--with-xslroot=${PREFIX}/share/xsl/docbook/
 PKGCONFIG_OVERRIDE=	jemalloc.pc.in
 
 REPLACE_PERL=		bin/jeprof.in
diff --git a/devel/jemalloc/distinfo b/devel/jemalloc/distinfo
index 84bd356c4c82..5cfd14828abd 100644
--- a/devel/jemalloc/distinfo
+++ b/devel/jemalloc/distinfo
@@ -1,8 +1,9 @@
-$NetBSD: distinfo,v 1.7 2017/08/27 12:12:25 adam Exp $
+$NetBSD: distinfo,v 1.8 2018/05/15 08:35:50 adam Exp $
 
-SHA1 (jemalloc-5.0.1.tar.bz2) = 5c2c74b8bf773df6e813f0709f55d40a8256104d
-RMD160 (jemalloc-5.0.1.tar.bz2) = f3e6fdbd4b5a00fde7de6a2d77c716a085b09943
-SHA512 (jemalloc-5.0.1.tar.bz2) = 8cb5957a5724eb2bbad120cf0028ea8b2b14b4a416c1751b7c967351a7fd51135058ea0d3c4dc1d127c86f3aa7e9fd5ef101857110aabfdb7789427791c432c3
-Size (jemalloc-5.0.1.tar.bz2) = 499300 bytes
+SHA1 (jemalloc-5.1.0.tar.bz2) = 92fdc0b38680aaee1fa7ccd89cbf1af61224ff46
+RMD160 (jemalloc-5.1.0.tar.bz2) = 52b1340ca8cafd7414aa5e3a7a028cb1feba0b80
+SHA512 (jemalloc-5.1.0.tar.bz2) = d9abebe54d303ca931b8c31c1033f23ff5fb060f2377ec8386f4d79c352e65c78ed34f680c352dac14f7d7115d10245782d553d988bc13df2eb34a2f0942ef6f
+Size (jemalloc-5.1.0.tar.bz2) = 515622 bytes
 SHA1 (patch-Makefile.in) = 62e04375dec9aab678fed5bc32559deb942e799f
+SHA1 (patch-configure) = 5dec3fb5b2ece549e40743780db3057dd83cc17e
 SHA1 (patch-src_pages.c) = 7c9eea2409b283c5dd80e52349c4dda26ae5befa
diff --git a/devel/jemalloc/patches/patch-configure b/devel/jemalloc/patches/patch-configure
new file mode 100644
index 000000000000..81349096384e
--- /dev/null
+++ b/devel/jemalloc/patches/patch-configure
@@ -0,0 +1,51 @@
+$NetBSD: patch-configure,v 1.3 2018/05/15 08:35:50 adam Exp $
+
+Do not use -O3, -g3, nor -funroll-loops; prefer PkgSrc provided compiler flags.
+
+--- configure.orig	2018-05-08 19:16:45.000000000 +0000
++++ configure
+@@ -4024,7 +4024,7 @@ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether compiler supports -g3" >&5
+ $as_echo_n "checking whether compiler supports -g3... " >&6; }
+ T_CONFIGURE_CFLAGS="${CONFIGURE_CFLAGS}"
+-T_APPEND_V=-g3
++T_APPEND_V=
+   if test "x${CONFIGURE_CFLAGS}" = "x" -o "x${T_APPEND_V}" = "x" ; then
+   CONFIGURE_CFLAGS="${CONFIGURE_CFLAGS}${T_APPEND_V}"
+ else
+@@ -5936,7 +5936,7 @@ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether compiler supports -g3" >&5
+ $as_echo_n "checking whether compiler supports -g3... " >&6; }
+ T_CONFIGURE_CXXFLAGS="${CONFIGURE_CXXFLAGS}"
+-T_APPEND_V=-g3
++T_APPEND_V=
+   if test "x${CONFIGURE_CXXFLAGS}" = "x" -o "x${T_APPEND_V}" = "x" ; then
+   CONFIGURE_CXXFLAGS="${CONFIGURE_CXXFLAGS}${T_APPEND_V}"
+ else
+@@ -8961,7 +8961,7 @@ if test "x$enable_debug" = "x0" ; then
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether compiler supports -O3" >&5
+ $as_echo_n "checking whether compiler supports -O3... " >&6; }
+ T_CONFIGURE_CFLAGS="${CONFIGURE_CFLAGS}"
+-T_APPEND_V=-O3
++T_APPEND_V=
+   if test "x${CONFIGURE_CFLAGS}" = "x" -o "x${T_APPEND_V}" = "x" ; then
+   CONFIGURE_CFLAGS="${CONFIGURE_CFLAGS}${T_APPEND_V}"
+ else
+@@ -9012,7 +9012,7 @@ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether compiler supports -O3" >&5
+ $as_echo_n "checking whether compiler supports -O3... " >&6; }
+ T_CONFIGURE_CXXFLAGS="${CONFIGURE_CXXFLAGS}"
+-T_APPEND_V=-O3
++T_APPEND_V=
+   if test "x${CONFIGURE_CXXFLAGS}" = "x" -o "x${T_APPEND_V}" = "x" ; then
+   CONFIGURE_CXXFLAGS="${CONFIGURE_CXXFLAGS}${T_APPEND_V}"
+ else
+@@ -9075,7 +9075,7 @@ fi
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether compiler supports -funroll-loops" >&5
+ $as_echo_n "checking whether compiler supports -funroll-loops... " >&6; }
+ T_CONFIGURE_CFLAGS="${CONFIGURE_CFLAGS}"
+-T_APPEND_V=-funroll-loops
++T_APPEND_V=
+   if test "x${CONFIGURE_CFLAGS}" = "x" -o "x${T_APPEND_V}" = "x" ; then
+   CONFIGURE_CFLAGS="${CONFIGURE_CFLAGS}${T_APPEND_V}"
+ else