diff --git a/Makefile.in b/Makefile.in
index 2b308f49ee..24ae13bac6 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -69,7 +69,7 @@ optflags = @optflags@
 debugflags = @debugflags@
 warnflags = @warnflags@ @strict_warnflags@
 cppflags = @cppflags@
-XCFLAGS = @XCFLAGS@ $(MJIT_CPPFLAGS)
+XCFLAGS = @XCFLAGS@
 CPPFLAGS = @CPPFLAGS@ $(INCFLAGS)
 MJIT_HEADER_FLAGS = @MJIT_HEADER_FLAGS@
 MJIT_HEADER_SUFFIX =
@@ -553,6 +553,8 @@ mjit_config.h:
 	echo '#ifndef RUBY_MJIT_CONFIG_H'; \
 	echo '#define RUBY_MJIT_CONFIG_H 1'; \
 	echo; \
+	sep=; \
+	quote MJIT_HEADER_INSTALL_DIR "$(MJIT_HEADER_INSTALL_DIR)"; \
 	sep=,; \
 	quote "MJIT_CC_COMMON  " $(CC); \
 	quote "MJIT_CFLAGS     " -w $(ARCH_FLAG); \
@@ -560,6 +562,7 @@ mjit_config.h:
 	quote "MJIT_DEBUGFLAGS " $(debugflags); \
 	quote "MJIT_LDSHARED   " @LDSHARED@; \
 	quote "MJIT_DLDFLAGS   " @DLDFLAGS@; \
+	quote "MJIT_LIBS       " $(LIBRUBYARG_SHARED); \
 	echo; \
 	echo '#endif /* RUBY_MJIT_CONFIG_H */'; \
 	} > $@
diff --git a/common.mk b/common.mk
index 9deb8cb3dd..69ab1a0733 100644
--- a/common.mk
+++ b/common.mk
@@ -61,8 +61,6 @@ HTMLOUT       = $(EXTOUT)/html
 CAPIOUT       = doc/capi
 MJIT_HEADER   = rb_mjit_header.h
 MJIT_MIN_HEADER = $(MJIT_HEADER_BUILD_DIR)/rb_mjit_min_header-$(RUBY_PROGRAM_VERSION).h
-MJIT_CPPFLAGS = -DMJIT_HEADER_INSTALL_DIR=\""$(MJIT_HEADER_INSTALL_DIR)"\" \
-		-DLIBRUBYARG_SHARED=\""$(LIBRUBYARG_SHARED)"\"
 MJIT_HEADER_BUILD_DIR = $(EXTOUT)/include/$(arch)
 
 INITOBJS      = dmyext.$(OBJEXT) dmyenc.$(OBJEXT)
diff --git a/mjit.c b/mjit.c
index 117e72f750..acd4ea3d27 100644
--- a/mjit.c
+++ b/mjit.c
@@ -647,7 +647,7 @@ compile_c_to_so(const char *c_file, const char *so_file)
     const char *libs[] = {
 #ifdef _WIN32
 # ifdef _MSC_VER
-        LIBRUBYARG_SHARED,
+        MJIT_LIBS
         "-link",
         libruby_installed,
         libruby_build,
@@ -655,8 +655,7 @@ compile_c_to_so(const char *c_file, const char *so_file)
         /* Look for ruby.dll.a in build and install directories. */
         libruby_installed,
         libruby_build,
-        /* Link to ruby.dll.a, because Windows DLLs don't allow unresolved symbols. */
-        LIBRUBYARG_SHARED,
+        MJIT_LIBS
         "-lmsvcrt",
         "-lgcc",
 # endif
diff --git a/win32/Makefile.sub b/win32/Makefile.sub
index 6cfb917acb..0cb1b6ba21 100644
--- a/win32/Makefile.sub
+++ b/win32/Makefile.sub
@@ -1010,7 +1010,6 @@ s,@top_srcdir@,$(srcdir),;t t
 s,@try_header@,try_compile,;t t
 s,@ruby_pc@,$(ruby_pc),;t t
 <<KEEP
-XCFLAGS = $(XCFLAGS) $(MJIT_CPPFLAGS)
 
 miniruby: miniruby$(EXEEXT)
 
@@ -1258,6 +1257,8 @@ mjit_config.h:
 	@echo making <<$@
 #ifndef RUBY_MJIT_CONFIG_H
 #define RUBY_MJIT_CONFIG_H 1
+
+#define MJIT_HEADER_INSTALL_DIR "$(MJIT_HEADER_INSTALL_DIR)"
 <<KEEP
 	@
 	@(set sep=#define MJIT_CC_COMMON ) & \
@@ -1284,5 +1285,10 @@ mjit_config.h:
 	for %I in ($(DLDFLAGS)) do @(call echo.%%sep%%"%%~I", \& set sep= ) >> $@
 	@echo /* MJIT_DLDFLAGS */>> $@
 	@
+	@(set sep=#define MJIT_LIBS ) & \
+	for %I in ($(LIBRUBYARG_SHARED)) do @(call echo.%%sep%%"%%~I", \& set sep= ) >> $@
+	@echo /* MJIT_LIBS */>> $@
+	@
+	@echo.>> $@
 	@echo #endif /* RUBY_MJIT_CONFIG_H */>> $@
 	@$(Q:@=: :) type $@