diff --git a/sdk/buildstep/toolchains.go b/sdk/buildstep/toolchains.go
index 6dc878f7..00d49555 100644
--- a/sdk/buildstep/toolchains.go
+++ b/sdk/buildstep/toolchains.go
@@ -13,15 +13,7 @@ import (
 // ToolchainNoReport is the reason AgreedToolchain gives when no node has reported a language's toolchain.
 const ToolchainNoReport = "toolchain not yet reported"
 
-// Toolchain is what a toolchain is identified by: the language, the installed version and the build module's recipe
-// version. It has the fields of the mesh-catalog client's Toolchain2, which a caller converts it to.
-type Toolchain struct {
-	Language string
-	Version  string
-	Recipe   string
-}
-
-// NodeToolchain is one node's entry of a language, as read from a build seat's state toolchains.
+// NodeToolchain is one node's entry of a language, as read from a build seat's state toolchains (the entry is Toolchain).
 type NodeToolchain struct {
 	Node string
 	Toolchain
@@ -35,7 +27,8 @@ type SittingOut struct {
 	Recipe  string
 }
 
-// Agreement is what the nodes' entries of one language come to. Toolchain is the agreed one, set when Wait is empty.
+// Agreement is what the nodes' entries of one language come to. Toolchain is the agreed one (its language, version and
+// recipe), set when Wait is empty.
 // Wait is why nothing is agreed: "toolchain not yet reported" with no entries, or "builders disagree" naming each version
 // and recipe with the nodes reporting it, when no version has a strict majority. SittingOut lists, sorted by node, the
 // nodes that report another version than the agreed one.
@@ -52,14 +45,15 @@ func ToolchainAgreement(entries []NodeToolchain) Agreement {
 	if len(entries) == 0 {
 		return Agreement{Wait: ToolchainNoReport}
 	}
-	groups := map[Toolchain][]string{}
+	type identity struct{ Language, Version, Recipe string }
+	groups := map[identity][]string{}
 	for _, e := range entries {
-		k := Toolchain{Language: e.Language, Version: e.Version, Recipe: e.Recipe}
+		k := identity{e.Language, e.Version, e.Recipe}
 		groups[k] = append(groups[k], e.Node)
 	}
 	for k, nodes := range groups {
 		if 2*len(nodes) > len(entries) {
-			a := Agreement{Toolchain: k}
+			a := Agreement{Toolchain: Toolchain{Language: k.Language, Version: k.Version, Recipe: k.Recipe}}
 			for _, e := range entries {
 				if e.Version != k.Version || e.Recipe != k.Recipe {
 					a.SittingOut = append(a.SittingOut, SittingOut{Node: e.Node, Version: e.Version, Recipe: e.Recipe})