diff --git a/sbank/overlap_cpu_lib.c b/sbank/overlap_cpu_lib.c
index c738840..e3bd425 100644
--- a/sbank/overlap_cpu_lib.c
+++ b/sbank/overlap_cpu_lib.c
@@ -23,6 +23,8 @@
 #include <sys/types.h>
 
 /* ---------------- LAL STUFF NEEDED ----------------- */
+int XLALPrintError(const char *fmt, ...);
+
 typedef struct tagCOMPLEX8Vector {
      uint32_t length; /**< Number of elements in array. */
      float complex *data; /**< Pointer to the data array. */
@@ -35,6 +37,8 @@ typedef struct tagCOMPLEX8FFTPlan COMPLEX8FFTPlan;
 
 COMPLEX8FFTPlan * XLALCreateReverseCOMPLEX8FFTPlan( uint32_t size, int measurelvl );
 
+int XLALCOMPLEX8VectorFFT (COMPLEX8Vector * restrict output, const COMPLEX8Vector * restrict input, const COMPLEX8FFTPlan *plan);
+
 void XLALDestroyCOMPLEX8FFTPlan( COMPLEX8FFTPlan *plan );
 
 /* ----------------------------------------------- */