diff --git a/.github/actions/build-postfix-exporter/action.yaml b/.github/actions/build-postfix-exporter/action.yaml
index f5a8b50..8e7fecf 100644
--- a/.github/actions/build-postfix-exporter/action.yaml
+++ b/.github/actions/build-postfix-exporter/action.yaml
@@ -68,7 +68,10 @@ runs:
         push: true
         tags: '${{ inputs.tags }}'
         labels: ${{ steps.meta.outputs.labels }}
-        platforms: "linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64/v8,linux/mips64le,linux/ppc64le,linux/s390x"
+        # linux/arm/v5 and linux/arm/v6 are not supported anymore by upstream Go docker images.
+        # Technically, we could build them but we would need to bootstrap the whole Go compiler.
+        # However, I'm not sure if it's worth it.
+        platforms: "linux/amd64,linux/arm/v7,linux/arm64/v8,linux/mips64le,linux/ppc64le,linux/s390x"
         # linux/386,linux/arm/v6,linux/arm64,linux/riscv64"
         cache-from: type=local,src=/tmp/.buildx-cache/postfix-exporter,mode=max,compression=estargz
         cache-to: type=local,dest=/tmp/.buildx-cache-new/postfix-exporter