diff --git a/make.config b/make.config
index b0a4736..4e7f847 100644
--- a/make.config
+++ b/make.config
@@ -4,6 +4,6 @@ IRPF90  ?= irpf90
 CC      ?= gcc
 FC      ?= gfortran -g -ffree-line-length-none -fPIC # -fopenmp
 FCFLAGS ?= -fPIC
-AR      ?= ar
+AR      ?= ar crs
 RANLIB  ?= ranlib
 PYTHON  ?= python3
diff --git a/src/Makefile b/src/Makefile
index 42cb4f6..78be935 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -50,13 +50,12 @@ IRPF90_temp/system_f.o: system_f.f90
 
 ../lib/libezfio.a: IRPF90_temp/irpf90.a
 	rm -f ../lib/libezfio.a
-	$(AR) cru ../lib/libezfio.a IRPF90_temp/system_f.o IRPF90_temp/system.o $(OBJ1)  
+	$(AR) ../lib/libezfio.a IRPF90_temp/system_f.o IRPF90_temp/system.o $(OBJ1)  
 	$(RANLIB) ../lib/libezfio.a
 
 ../lib/libezfio_irp.a: ../lib/libezfio.a
 	rm -f ../lib/libezfio_irp.a
-	cp ../lib/libezfio.a ../lib/libezfio_irp.a
-	$(AR) dv ../lib/libezfio_irp.a irp_stack.irp.o
+	$(AR) ../lib/libezfio_irp.a IRPF90_temp/system_f.o IRPF90_temp/system.o $(filter-out IRPF90_temp/irp_stack.irp.o, $(OBJ1) )
 	$(RANLIB) ../lib/libezfio_irp.a
 
 
diff --git a/src/create_ocaml.py b/src/create_ocaml.py
index d1985b5..00788bc 100755
--- a/src/create_ocaml.py
+++ b/src/create_ocaml.py
@@ -46,7 +46,7 @@ def run():
   
   for group in groups.keys():
      for var,type,dims,command in groups[group]:
-       if command is not "":
+       if command != "":
          continue
        dims_py = str(dims)
        for g in groups.keys():