--- old/make/linux/makefiles/jsig.make	2019-07-09 12:01:02.426187782 +0200
+++ new/make/linux/makefiles/jsig.make	2019-07-09 12:01:02.167187293 +0200
@@ -51,10 +51,15 @@
   JSIG_DEBUG_CFLAGS = -g
 endif
 
+# Optimize jsig lib at level -O3 unless it's a slowdebug build
+ifneq ($(DEBUG_LEVEL), slowdebug)
+  JSIG_OPT_FLAGS = $(OPT_CFLAGS)
+endif
+
 $(LIBJSIG): $(JSIGSRCDIR)/jsig.c $(LIBJSIG_MAPFILE)
 	@echo Making signal interposition lib...
 	$(QUIETLY) $(CC) $(SYMFLAG) $(ARCHFLAG) $(SHARED_FLAG) $(PICFLAG) \
-                         $(LFLAGS_JSIG) $(JSIG_DEBUG_CFLAGS) $(EXTRA_CFLAGS) -o $@ $< -ldl
+                         $(LFLAGS_JSIG) $(JSIG_DEBUG_CFLAGS) $(JSIG_OPT_FLAGS) $(EXTRA_CFLAGS) -o $@ $< -ldl
 ifeq ($(ENABLE_FULL_DEBUG_SYMBOLS),1)
   ifneq ($(STRIP_POLICY),no_strip)
 	$(QUIETLY) $(OBJCOPY) --only-keep-debug $@ $(LIBJSIG_DEBUGINFO)