diff -r 75db54c6c259 -r 6ea3ec6b1edc make/CompileJavaModules.gmk
--- a/make/CompileJavaModules.gmk	Mon Sep 21 11:01:19 2015 +0200
+++ b/make/CompileJavaModules.gmk	Mon Sep 21 20:56:16 2015 +0300
@@ -42,7 +42,7 @@
 
 ################################################################################
 
-java.base_ADD_JAVAC_FLAGS := -Xdoclint:all/protected,-reference '-Xdoclint/package:java.*,javax.*'
+java.base_ADD_JAVAC_FLAGS := -Xdoclint:all/protected,-reference '-Xdoclint/package:java.*,javax.*' -XstringConcat:inline
 java.base_COPY := .icu .dat .spp content-types.properties hijrah-config-islamic-umalqura.properties
 java.base_CLEAN := intrinsic.properties
 
@@ -353,7 +353,7 @@
 
 ################################################################################
 
-jdk.compiler_ADD_JAVAC_FLAGS := -Xdoclint:all/protected '-Xdoclint/package:-com.sun.tools.*'
+jdk.compiler_ADD_JAVAC_FLAGS := -Xdoclint:all/protected '-Xdoclint/package:-com.sun.tools.*' -XstringConcat:inline
 jdk.compiler_COPY := javax.tools.JavaCompilerTool
 jdk.compiler_CLEAN_FILES := $(wildcard \
     $(patsubst %, $(JDK_TOPDIR)/src/jdk.compiler/share/classes/%/*.properties, \
diff -r 75db54c6c259 -r 6ea3ec6b1edc make/common/SetupJavaCompilers.gmk
--- a/make/common/SetupJavaCompilers.gmk	Mon Sep 21 11:01:19 2015 +0200
+++ b/make/common/SetupJavaCompilers.gmk	Mon Sep 21 20:56:16 2015 +0300
@@ -53,7 +53,7 @@
 $(eval $(call SetupJavaCompiler,GENERATE_OLDBYTECODE, \
     JVM := $(JAVA_SMALL), \
     JAVAC := $(NEW_JAVAC), \
-    FLAGS := $(BOOT_JDK_SOURCETARGET) -XDignore.symbol.file=true \
+    FLAGS := $(BOOT_JDK_SOURCETARGET) -XDignore.symbol.file=true -XstringConcat:inline \
         $(DISABLE_WARNINGS) -Xlint:-options, \
     SERVER_DIR := $(SJAVAC_SERVER_DIR), \
     SERVER_JVM := $(SJAVAC_SERVER_JAVA)))