diff --git a/gb.gsl/src/c_gsl.h b/gb.gsl/src/c_gsl.h
index 997fd10a4..45bee674a 100644
--- a/gb.gsl/src/c_gsl.h
+++ b/gb.gsl/src/c_gsl.h
@@ -28,7 +28,7 @@
 
 #include "gambas.h"
 
-GB_INTERFACE GB EXPORT;
+extern GB_INTERFACE GB EXPORT;
 
 #ifndef __C_GSL_C
 extern GB_DESC CGslDesc[];
diff --git a/gb.gsl/src/c_polynomial.h b/gb.gsl/src/c_polynomial.h
index c198ac5f1..e2105bdbe 100644
--- a/gb.gsl/src/c_polynomial.h
+++ b/gb.gsl/src/c_polynomial.h
@@ -30,7 +30,7 @@
 #include <gsl/gsl_poly.h>
 #include <gsl/gsl_sf_result.h>
  
-GB_INTERFACE GB EXPORT;
+extern GB_INTERFACE GB EXPORT;
 
 extern GB_DESC PolynomialDesc[];