diff --git a/libvips/conversion/premultiply.c b/libvips/conversion/premultiply.c
index 0560237e..11e7466d 100644
--- a/libvips/conversion/premultiply.c
+++ b/libvips/conversion/premultiply.c
@@ -281,7 +281,7 @@ vips_premultiply_init( VipsPremultiply *premultiply )
  *   alpha = clip( 0, in[in.bands - 1], @max_alpha ); 
  *   norm = alpha / @max_alpha; 
  *   out = [in[0] * norm, ..., in[in.bands - 1] * norm, alpha];
- * |]
+ * ]|
  *
  * So for an N-band image, the first N - 1 bands are multiplied by the clipped 
  * and normalised final band, the final band is clipped. 
diff --git a/libvips/conversion/unpremultiply.c b/libvips/conversion/unpremultiply.c
index 28e998a3..6105d1e5 100644
--- a/libvips/conversion/unpremultiply.c
+++ b/libvips/conversion/unpremultiply.c
@@ -296,7 +296,7 @@ vips_unpremultiply_init( VipsUnpremultiply *unpremultiply )
  *   	out = [0, ..., 0, alpha];
  *   else
  *   	out = [in[0] / norm, ..., in[in.bands - 1] / norm, alpha];
- * |]
+ * ]|
  *
  * So for an N-band image, the first N - 1 bands are divided by the clipped 
  * and normalised final band, the final band is clipped.