--- a/make/autoconf/toolchain.m4	Wed Dec 19 00:50:05 2018 -0800
+++ b/make/autoconf/toolchain.m4	Wed Dec 19 03:35:40 2018 -0800
@@ -331,15 +331,15 @@
       && test "x$TOOLCHAIN_TYPE" = "xmicrosoft"; then
     TOOLCHAIN_SETUP_VISUAL_STUDIO_ENV
     if test "x$OPENJDK_BUILD_OS_ENV" = "xwindows.wsl"; then
-      # Append VS_PATH
+      # Append VS_PATH. In WSL, VS_PATH will not contain the WSL env path needed
+      # for using basic Unix tools, so need to keep the original PATH.
       BASIC_APPEND_TO_PATH(PATH, $VS_PATH)
       BASIC_APPEND_TO_PATH(WSLENV, "PATH/l:LIB:INCLUDE")
       export WSLENV
     else
       # Reset path to VS_PATH. It will include everything that was on PATH at the time we
       # ran TOOLCHAIN_SETUP_VISUAL_STUDIO_ENV.
-      BASIC_APPEND_TO_PATH(PATH, $VS_PATH)
-      AC_MSG_NOTICE(PATH $PATH)
+      PATH="$VS_PATH"
     fi
     # The microsoft toolchain also requires INCLUDE and LIB to be set.
     export INCLUDE="$VS_INCLUDE"

--- a/make/autoconf/toolchain_windows.m4	Wed Dec 19 00:50:05 2018 -0800
+++ b/make/autoconf/toolchain_windows.m4	Wed Dec 19 03:35:40 2018 -0800
@@ -483,26 +483,28 @@
       AC_SUBST(VS_INCLUDE)
       AC_SUBST(VS_LIB)
 
-      # Convert VS_PATH to unix style
       OLDIFS="$IFS"
       IFS=";"
-      VS_PATH_WINDOWS="$VS_PATH"
-      VS_PATH=""
-      for i in $VS_PATH_WINDOWS; do
-        path=$i
-        # Only process non-empty elements
-        if test "x$path" != x; then
-          IFS="$OLDIFS"
-          # Check that directory exists before calling fixup_path
-          testpath=$path
-          BASIC_WINDOWS_REWRITE_AS_UNIX_PATH([testpath])
-          if test -d "$testpath"; then
-            BASIC_FIXUP_PATH([path])
-            BASIC_APPEND_TO_PATH(VS_PATH, $path)
+      if test "x$OPENJDK_BUILD_OS_ENV" = "xwindows.wsl"; then
+        # Convert VS_PATH to unix style
+        VS_PATH_WINDOWS="$VS_PATH"
+        VS_PATH=""
+        for i in $VS_PATH_WINDOWS; do
+          path=$i
+          # Only process non-empty elements
+          if test "x$path" != x; then
+            IFS="$OLDIFS"
+            # Check that directory exists before calling fixup_path
+            testpath=$path
+            BASIC_WINDOWS_REWRITE_AS_UNIX_PATH([testpath])
+            if test -d "$testpath"; then
+              BASIC_FIXUP_PATH([path])
+              BASIC_APPEND_TO_PATH(VS_PATH, $path)
+            fi
+            IFS=";"
           fi
-          IFS=";"
-        fi
-      done
+        done
+      fi
       # Convert VS_INCLUDE into SYSROOT_CFLAGS
       for i in $VS_INCLUDE; do
         ipath=$i