diff --git a/Makefile.in b/Makefile.in
index 9eb3026..8cc9341 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -86,7 +86,7 @@ GENERATED= src/version.ml
 
 CAMLIBS	= $(addprefix -I , $(DIRS))
 
-CAMLFLAGS= $(CAMLIBS)
+CAMLFLAGS= -g $(CAMLIBS)
 BYTEFLAGS= $(CAMLFLAGS)
 LINK_OPTFLAGS = $(CAMLFLAGS) -noassert
 OPTFLAGS = $(LINK_OPTFLAGS) -for-pack CalendarLib