diff --git a/libvips/morphology/countlines.c b/libvips/morphology/countlines.c
index 7fbdc85b..0812dee1 100644
--- a/libvips/morphology/countlines.c
+++ b/libvips/morphology/countlines.c
@@ -157,9 +157,9 @@ vips_countlines_init( VipsCountlines *countlines )
 }
 
 /**
- * vips_countlines:
+ * vips_countlines: (method)
  * @in: input image
- * @nolines: output average number of lines
+ * @nolines: (out): output average number of lines
  * @direction: count lines horizontally or vertically
  * @...: %NULL-terminated list of optional named arguments
  *
diff --git a/libvips/morphology/labelregions.c b/libvips/morphology/labelregions.c
index 880b21be..161fb754 100644
--- a/libvips/morphology/labelregions.c
+++ b/libvips/morphology/labelregions.c
@@ -142,7 +142,7 @@ vips_labelregions_init( VipsLabelregions *labelregions )
 }
 
 /**
- * vips_labelregions:
+ * vips_labelregions: (method)
  * @in: image to test
  * @mask: write labelled regions here
  * @...: %NULL-terminated list of optional named arguments
diff --git a/libvips/morphology/morph.c b/libvips/morphology/morph.c
index 5b38d00e..d19833a0 100644
--- a/libvips/morphology/morph.c
+++ b/libvips/morphology/morph.c
@@ -168,9 +168,9 @@ vips_morph_init( VipsMorph *morph )
 }
 
 /**
- * vips_morph:
+ * vips_morph: (method)
  * @in: input image
- * @out: output image
+ * @out: (out): output image
  * @mask: morphology with this mask
  * @morph: operation to perform
  * @...: %NULL-terminated list of optional named arguments
diff --git a/libvips/morphology/rank.c b/libvips/morphology/rank.c
index fea8e211..d0a52851 100644
--- a/libvips/morphology/rank.c
+++ b/libvips/morphology/rank.c
@@ -447,9 +447,9 @@ vips_rank_init( VipsRank *rank )
 }
 
 /**
- * vips_rank:
+ * vips_rank: (method)
  * @in: input image
- * @out: output image
+ * @out: (out): output image
  * @width: width of region
  * @height: height of region
  * @index: select pixel
@@ -491,9 +491,9 @@ vips_rank( VipsImage *in, VipsImage **out,
 }
 
 /**
- * vips_median:
+ * vips_median: (method)
  * @in: input image
- * @out: output image
+ * @out: (out): output image
  * @size: size of region
  * @...: %NULL-terminated list of optional named arguments
  *