diff --git a/CHANGELOG.md b/CHANGELOG.md
index 9a999b86..b4edc6b3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -19,6 +19,7 @@
 - Fix wrong colors when the source image has a linear colorspace.
 - Fix wrong colors or opacity when the source image is a TIFF with a float sample format.
 - Fix crashes during processing of large animated WebPs.
+- Fix `vips_allocs` OTel metric unit (was `By`, fixed to `1`).
 - (pro) Fix generating thumbnails for WebM videos with transparency.
 - (pro) Fix style injection into some SVGs.
 
diff --git a/vips/vips.go b/vips/vips.go
index 0d35a8f9..4cdf731f 100644
--- a/vips/vips.go
+++ b/vips/vips.go
@@ -130,7 +130,7 @@ func Init() error {
 	otel.AddGaugeFunc(
 		"vips_allocs",
 		"A gauge of the number of active vips allocations.",
-		"By",
+		"1",
 		GetAllocs,
 	)