diff --git a/qpms/qpms_types.h b/qpms/qpms_types.h
index 6d34e46..98bd7d1 100644
--- a/qpms/qpms_types.h
+++ b/qpms/qpms_types.h
@@ -280,6 +280,26 @@ typedef struct qpms_irot3_t {
         short det; ///< Determinant of the transformation (valid values are 1 (rotation) or -1 (improper rotation)
 } qpms_irot3_t;
 
+/// Specifies a finite set of VSWFs.
+/**
+ * When for example not all the M and N -type waves up to a degree lMax
+ * need to be computed, this will specify the subset.
+ *
+ * A typical use case would be when only even/odd fields wrt. z-plane
+ * mirror symmetry are considered.
+ * 
+ * Check vswf.h for "methods".
+ */
+typedef struct qpms_vswf_set_spec_t {
+        size_t n; ///< Actual number of VSWF indices included in ilist.
+        qpms_uvswfi_t *ilist; ///< List of wave indices.
+        qpms_l_t lMax; ///< Maximum degree of the waves specified in ilist.
+        qpms_l_t lMax_M, ///< Maximum degree of the magnetic (M-type) waves.
+                 lMax_N, ///< Maximum degree of the electric (N-type) waves.
+                 lMax_L; ///< Maximum degree of the longitudinal (L-type) waves.
+        size_t capacity; ///< Allocated capacity of ilist.
+        qpms_normalisation_t norm; ///< Normalisation convention. To be set manually if needed.
+} qpms_vswf_set_spec_t;
 
 #define lmcheck(l,m) assert((l) >= 1 && abs(m) <= (l))
 #endif // QPMS_TYPES
diff --git a/qpms/scatsystem.h b/qpms/scatsystem.h
index 2a20bb1..34c32c3 100644
--- a/qpms/scatsystem.h
+++ b/qpms/scatsystem.h
@@ -3,7 +3,7 @@
  */
 #ifndef QPMS_SCATSYSTEM_H
 #define QPMS_SCATSYSTEM_H
-#include "vswf.h"
+#include "qpms_types.h"
 #include <stdbool.h>
 #include <gsl/gsl_spline.h>
 
diff --git a/qpms/symmetries.h b/qpms/symmetries.h
index 4548ff0..9e4266a 100644
--- a/qpms/symmetries.h
+++ b/qpms/symmetries.h
@@ -21,7 +21,6 @@
  */
 #ifndef SYMMETRIES_H
 #define SYMMETRIES_H
-#include "vswf.h"
 #include "qpms_types.h"
 #include <cblas.h>
 
diff --git a/qpms/vswf.h b/qpms/vswf.h
index 79e8bdb..5c74ca0 100644
--- a/qpms/vswf.h
+++ b/qpms/vswf.h
@@ -10,24 +10,7 @@
 #include "qpms_types.h"
 #include <gsl/gsl_sf_legendre.h>
 
-/// Specifies a finite set of VSWFs.
-/**
- * When for example not all the M and N -type waves up to a degree lMax
- * need to be computed, this will specify the subset. 
- *
- * A typical use case would be when only even/odd fields wrt. z-plane
- * mirror symmetry are considered.
- */
-typedef struct qpms_vswf_set_spec_t {
-	size_t n; ///< Actual number of VSWF indices included in ilist.
-	qpms_uvswfi_t *ilist; ///< List of wave indices.
-	qpms_l_t lMax; ///< Maximum degree of the waves specified in ilist.
-	qpms_l_t lMax_M, ///< Maximum degree of the magnetic (M-type) waves.
-		 lMax_N, ///< Maximum degree of the electric (N-type) waves.
-		 lMax_L; ///< Maximum degree of the longitudinal (L-type) waves.
-	size_t capacity; ///< Allocated capacity of ilist.
-	qpms_normalisation_t norm; ///< Normalisation convention. To be set manually if needed.
-} qpms_vswf_set_spec_t;
+// Methods for qpms_vswf_spec_t
 /// Creates a qpms_vswf_set_spec_t structure with an empty list of wave indices.
 qpms_vswf_set_spec_t *qpms_vswf_set_spec_init();
 /// Appends a VSWF index to a \ref qpms_vswf_set_spec_t, also updating metadata.