diff --git a/Makefile.in b/Makefile.in
index 3bfeb363..3f4d5046 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -40,6 +40,10 @@ ifeq "$(GMOCK_DIR)" ""
 GMOCK_DIR := $(srcdir)/third_party/googletest/googlemock
 endif
 
+# Force the simple internal regex engine to get consistent behavior on all platforms.
+# See https://code.google.com/p/chromium/issues/detail?id=317224 for more details.
+GTEST_FLAGS := -DGTEST_HAS_POSIX_RE=0 -I$(GMOCK_DIR)/include -I$(GTEST_DIR)/include
+
 LIB_SRCS  := ZNCString.cpp Csocket.cpp znc.cpp IRCNetwork.cpp User.cpp IRCSock.cpp \
 	Client.cpp Chan.cpp Nick.cpp Server.cpp Modules.cpp MD5.cpp Buffer.cpp Utils.cpp \
 	FileUtils.cpp HTTPSock.cpp Template.cpp ClientCommand.cpp Socket.cpp SHA256.cpp \
@@ -123,22 +127,22 @@ src/%.o: src/%.cpp Makefile include/znc/Csocket.h
 test/%.o: test/%.cpp Makefile include/znc/Csocket.h
 	@mkdir -p .depend test
 	$(E) Building test object $*...
-	$(Q)$(CXX) $(CXXFLAGS) -I$(GMOCK_DIR)/include -I$(GTEST_DIR)/include -c -o $@ $< -MD -MF .depend/$*.test.dep -MT $@
+	$(Q)$(CXX) $(CXXFLAGS) $(GTEST_FLAGS) -c -o $@ $< -MD -MF .depend/$*.test.dep -MT $@
 
 test/gtest-all.o: $(GTEST_DIR)/src/gtest-all.cc Makefile
 	@mkdir -p .depend test
 	$(E) Building test object gtest-all...
-	$(Q)$(CXX) $(CXXFLAGS) -I$(GTEST_DIR)/include -I$(GTEST_DIR) -c -o $@ $< -MD -MF .depend/gtest-all.dep -MT $@
+	$(Q)$(CXX) $(CXXFLAGS) $(GTEST_FLAGS) -I$(GTEST_DIR) -c -o $@ $< -MD -MF .depend/gtest-all.dep -MT $@
 
 test/gmock-all.o: $(GMOCK_DIR)/src/gmock-all.cc Makefile
 	@mkdir -p .depend test
 	$(E) Building test object gmock-all...
-	$(Q)$(CXX) $(CXXFLAGS) -I$(GMOCK_DIR)/include -I$(GTEST_DIR)/include -I$(GMOCK_DIR) -c -o $@ $< -MD -MF .depend/gmock-all.dep -MT $@
+	$(Q)$(CXX) $(CXXFLAGS) $(GTEST_FLAGS) -I$(GMOCK_DIR) -c -o $@ $< -MD -MF .depend/gmock-all.dep -MT $@
 
 test/gmock-main.o: $(GMOCK_DIR)/src/gmock_main.cc Makefile
 	@mkdir -p .depend test
 	$(E) Building test object gmock-main...
-	$(Q)$(CXX) $(CXXFLAGS) -I$(GMOCK_DIR)/include -I$(GTEST_DIR)/include -c -o $@ $< -MD -MF .depend/gmock-main.dep -MT $@
+	$(Q)$(CXX) $(CXXFLAGS) $(GTEST_FLAGS) -c -o $@ $< -MD -MF .depend/gmock-main.dep -MT $@
 
 ifneq "THIS_IS_NOT_TARBALL" ""
 # If git commit was changed since previous build, add a phony target to dependencies, forcing version.o to be recompiled