diff --git a/Code/Mantid/Framework/SINQ/inc/MantidSINQ/PoldiUtilities/PeakFunctionIntegrator.h b/Code/Mantid/Framework/SINQ/inc/MantidSINQ/PoldiUtilities/PeakFunctionIntegrator.h
index 057752ee31f9..2617a3cf7909 100644
--- a/Code/Mantid/Framework/SINQ/inc/MantidSINQ/PoldiUtilities/PeakFunctionIntegrator.h
+++ b/Code/Mantid/Framework/SINQ/inc/MantidSINQ/PoldiUtilities/PeakFunctionIntegrator.h
@@ -69,7 +69,7 @@ class MANTID_SINQ_DLL PeakFunctionIntegrator {
     double m_relativePrecision;
 };
 
-double gsl_peak_wrapper(double x, void *parameters);
+double MANTID_SINQ_DLL gsl_peak_wrapper(double x, void *parameters);
 
 }
 }