diff --git a/python/extrules.am b/python/extrules.am
index 543cc4b5a..a62a96f9f 100644
--- a/python/extrules.am
+++ b/python/extrules.am
@@ -1,5 +1,5 @@
 swig : gribapi_swig.i
-	swig -python -module gribapi_swig -DNUMPY -o swig_wrap_numpy.c gribapi_swig.i
+	swig -python -module gribapi_swig -o swig_wrap_numpy.c gribapi_swig.i
 	cp gribapi_swig.py swig_wrap_numpy.py
 
 #	swig -python -module gribapi_swig -o swig_wrap_array.c gribapi_swig.i
diff --git a/python/gribapi_swig.i b/python/gribapi_swig.i
index 7940427ff..9d13c362a 100644
--- a/python/gribapi_swig.i
+++ b/python/gribapi_swig.i
@@ -140,6 +140,7 @@ int grib_c_set_key_vals(int* gid, char* keyvals);
 int grib_c_is_missing(int* gid, char* key, int* OUTPUT);
 int grib_c_is_defined(int* gid, char* key, int* OUTPUT);
 
+// Numpy Support
 %apply (double* IN_ARRAY1, int DIM1) {(double* dpin_val, int dpin_val_dim1)};
 %apply (long* IN_ARRAY1, int DIM1) {(long* lpin_val, int lpin_val_dim1)};
 %apply (int* IN_ARRAY1, int DIM1) {(int* ipin_index, int ipin_index_dim1)};