--- a/build/moz.configure/memory.configure
+++ b/build/moz.configure/memory.configure
@@ -50,8 +50,31 @@ add_old_configure_assignment('MOZ_JEMALL
 # through the old-configure.
 @depends(jemalloc, jemalloc4)
 def jemalloc_for_old_configure(jemalloc, jemalloc4):
     if jemalloc:
         return '--enable-jemalloc=4' if jemalloc4 else '--enable-jemalloc'
     return '--disable-jemalloc'
 
 add_old_configure_arg(jemalloc_for_old_configure)
+
+
+@depends(jemalloc, jemalloc4, target)
+def jemalloc_os_define(jemalloc, jemalloc4, target):
+    if jemalloc and not jemalloc4:
+        if target.kernel == 'WINNT':
+            return 'MOZ_MEMORY_WINDOWS'
+        if target.kernel == 'Linux':
+            return 'MOZ_MEMORY_LINUX'
+        if target.kernel == 'Darwin':
+            return 'MOZ_MEMORY_DARWIN'
+        if target.kernel in ('kFreeBSD', 'FreeBSD', 'NetBSD'):
+            return 'MOZ_MEMORY_BSD'
+        die('--enable-jemalloc is not supported on %s', target.kernel)
+
+set_define(jemalloc_os_define, '1')
+
+@depends(jemalloc, jemalloc4, target)
+def jemalloc_os_define_android(jemalloc, jemalloc4, target):
+    if jemalloc and not jemalloc4 and target.os == 'Android':
+        return 'MOZ_MEMORY_ANDROID'
+
+set_define(jemalloc_os_define_android, '1')

--- a/js/src/old-configure.in
+++ b/js/src/old-configure.in
@@ -1989,39 +1989,19 @@ esac
 if test "$MOZ_MEMORY"; then
   if test "x$MOZ_DEBUG" = "x1"; then
     AC_DEFINE(MOZ_MEMORY_DEBUG)
   fi
   dnl The generic feature tests that determine how to compute ncpus are long and
   dnl complicated.  Therefore, simply define special cpp variables for the
   dnl platforms we have special knowledge of.
   case "${target}" in
-  *-darwin*)
-    AC_DEFINE(MOZ_MEMORY_DARWIN)
-    ;;
-  *-*freebsd*)
-    AC_DEFINE(MOZ_MEMORY_BSD)
-    ;;
-  *-android*|*-linuxandroid*)
-    AC_DEFINE(MOZ_MEMORY_LINUX)
-    AC_DEFINE(MOZ_MEMORY_ANDROID)
-    ;;
-  *-*linux*)
-    AC_DEFINE(MOZ_MEMORY_LINUX)
-    ;;
-  *-netbsd*)
-    AC_DEFINE(MOZ_MEMORY_BSD)
-    ;;
   *-mingw*)
-    AC_DEFINE(MOZ_MEMORY_WINDOWS)
     export MOZ_NO_DEBUG_RTL=1
     ;;
-  *)
-    AC_MSG_ERROR([--enable-jemalloc not supported on ${target}])
-    ;;
   esac
 fi
 AC_SUBST(MOZ_CRT)
 AC_SUBST(MOZ_GLUE_IN_PROGRAM)
 AC_SUBST_LIST(MOZ_GLUE_WRAP_LDFLAGS)
 
 dnl ========================================================
 dnl = Use a smaller chunk size for GC chunks

--- a/old-configure.in
+++ b/old-configure.in
@@ -5708,49 +5708,29 @@ else
   fi
   if test "x$MOZ_DEBUG" = "x1"; then
     AC_DEFINE(MOZ_MEMORY_DEBUG)
   fi
   dnl The generic feature tests that determine how to compute ncpus are long and
   dnl complicated.  Therefore, simply define special cpp variables for the
   dnl platforms we have special knowledge of.
   case "${target}" in
-  *-darwin*)
-    AC_DEFINE(MOZ_MEMORY_DARWIN)
-    ;;
-  *-*freebsd*)
-    AC_DEFINE(MOZ_MEMORY_BSD)
-    ;;
-  *-android*|*-linuxandroid*)
-    AC_DEFINE(MOZ_MEMORY_LINUX)
-    AC_DEFINE(MOZ_MEMORY_ANDROID)
-    ;;
-  *-*linux*)
-    AC_DEFINE(MOZ_MEMORY_LINUX)
-    ;;
-  *-netbsd*)
-    AC_DEFINE(MOZ_MEMORY_BSD)
-    ;;
   *-mingw*)
-    AC_DEFINE(MOZ_MEMORY_WINDOWS)
     export MOZ_NO_DEBUG_RTL=1
     if test "$MSVS_VERSION" != "2015"; then
         WIN32_CRT_LIBS="msvcrt.lib msvcprt.lib"
         dnl Look for a broken crtdll.obj
         WIN32_CRTDLL_FULLPATH=`lib -nologo -list $WIN32_CRT_LIBS | grep crtdll\\.obj`
         lib -NOLOGO -OUT:crtdll.obj $WIN32_CRT_LIBS -EXTRACT:$WIN32_CRTDLL_FULLPATH
         if grep -q '__imp__\{0,1\}free' crtdll.obj; then
           MOZ_CRT=1
         fi
         rm crtdll.obj
     fi
     ;;
-  *)
-    AC_MSG_ERROR([--enable-jemalloc not supported on ${target}])
-    ;;
   esac
 fi # MOZ_MEMORY
 AC_SUBST(MOZ_SYSTEM_JEMALLOC)
 AC_SUBST(MOZ_CRT)
 export MOZ_CRT
 AC_SUBST(MOZ_GLUE_IN_PROGRAM)
 AC_SUBST_LIST(WIN32_CRT_LIBS)