--- Makefile
+++ Makefile
@@ -139,7 +139,10 @@
 
 # Targets
 
+VERSION=1.0.13
+MAJOR_VERSION=$(firstword $(subst ., ,$(VERSION)))
 LIBGSM	= $(LIB)/libgsm.a
+LIBGSMSO= $(LIB)/libgsm.so.$(VERSION)
 
 TOAST	= $(BIN)/toast
 UNTOAST	= $(BIN)/untoast
@@ -279,7 +282,7 @@
 
 # Target rules
 
-all:		$(LIBGSM) $(TOAST) $(TCAT) $(UNTOAST)
+all:		$(LIBGSM) $(LIBGSMSO) $(TOAST) $(TCAT) $(UNTOAST)
 		@-echo $(ROOT): Done.
 
 tst:		$(TST)/lin2cod $(TST)/cod2lin $(TOAST) $(TST)/test-result
@@ -304,6 +307,11 @@
 		$(AR) $(ARFLAGS) $(LIBGSM) $(GSM_OBJECTS)
 		$(RANLIB) $(LIBGSM)
 
+$(LIBGSMSO):	$(LIB) $(GSM_OBJECTS)
+	$(CC) $(LDFLAGS) -shared -Wl,-soname,libgsm.so.$(MAJOR_VERSION) -o $@ $(GSM_OBJECTS)
+	$(LN) -sf $(notdir $@) lib/libgsm.so.$(MAJOR_VERSION)
+	$(LN) -sf $(notdir $@) lib/libgsm.so
+
 
 # Toast, Untoast and Tcat -- the compress-like frontends to gsm.
 
@@ -425,7 +433,7 @@
 			-print | xargs rm $(RMFLAGS)
 
 clean:	semi-clean
-		-rm $(RMFLAGS) $(LIBGSM) $(ADDTST)/add		\
+		-rm $(RMFLAGS) $(LIBGSM) lib/libgsm.so* $(ADDTST)/add		\
 			$(TOAST) $(TCAT) $(UNTOAST)	\
 			$(ROOT)/gsm-1.0.tar.Z