diff --git a/mk2rbc/mk2rbc.go b/mk2rbc/mk2rbc.go
index d1140fa..d5ff181 100644
--- a/mk2rbc/mk2rbc.go
+++ b/mk2rbc/mk2rbc.go
@@ -1332,6 +1332,34 @@
 			// TODO (asmundak): if we find many, maybe handle them.
 			return ctx.newBadExpr(node, "SOONG_CONFIG_ variables cannot be referenced, use soong_config_get instead: %s", refDump)
 		}
+		// Handle substitution references: https://www.gnu.org/software/make/manual/html_node/Substitution-Refs.html
+		if strings.Contains(refDump, ":") {
+			parts := strings.SplitN(refDump, ":", 2)
+			substParts := strings.SplitN(parts[1], "=", 2)
+			if len(substParts) < 2 || strings.Count(substParts[0], "%") > 1 {
+				return ctx.newBadExpr(node, "Invalid substitution reference")
+			}
+			if !strings.Contains(substParts[0], "%") {
+				if strings.Contains(substParts[1], "%") {
+					return ctx.newBadExpr(node, "A substitution reference must have a %% in the \"before\" part of the substitution if it has one in the \"after\" part.")
+				}
+				substParts[0] = "%" + substParts[0]
+				substParts[1] = "%" + substParts[1]
+			}
+			v := ctx.addVariable(parts[0])
+			if v == nil {
+				return ctx.newBadExpr(node, "unknown variable %s", refDump)
+			}
+			return &callExpr{
+				name:       "patsubst",
+				returnType: knownFunctions["patsubst"].returnType,
+				args: []starlarkExpr{
+					&stringLiteralExpr{literal: substParts[0]},
+					&stringLiteralExpr{literal: substParts[1]},
+					&variableRefExpr{v, ctx.lastAssignment(v.name()) != nil},
+				},
+			}
+		}
 		if v := ctx.addVariable(refDump); v != nil {
 			return &variableRefExpr{v, ctx.lastAssignment(v.name()) != nil}
 		}