diff --git a/lib/Makefile b/lib/Makefile
index db5540f..5b077da 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -1,6 +1,6 @@
 include ../config
 
-STDLIB_INTERFACE=pervasives.epi
+STDLIB_INTERFACE=pervasives.epi iostream.epi
 STDLIB_OBJ=$(STDLIB_INTERFACE:.epi=.epci)
 
 C_DIR=c
@@ -8,13 +8,16 @@ C_OBJ=pervasives.h
 
 .SUFFIXES: .epi .epci
 
-.epi.epci:
-	../compiler/$(COMPILER).$(TARGET) -nopervasives $<
-
 .PHONY: all install clean
 
 all: $(STDLIB_OBJ)
 
+pervasives.epci: pervasives.epi
+	../compiler/$(COMPILER).$(TARGET) -nopervasives $<
+
+%.epci: %.epi
+	../compiler/$(COMPILER).$(TARGET) $<
+
 install: all
 	$(INSTALL) -d $(INSTALL_LIBDIR)
 	$(INSTALL) $(STDLIB_OBJ) $(STDLIB_INTERFACE) $(INSTALL_LIBDIR)
@@ -22,4 +25,5 @@ install: all
 	(cd c/; $(INSTALL) $(C_OBJ) $(INSTALL_LIBDIR)/$(C_DIR))
 
 clean:
-	rm -f *.epci
\ No newline at end of file
+	rm -f *.epci
+