diff --git a/src/cmd/compile/internal/inline/inl.go b/src/cmd/compile/internal/inline/inl.go
index 8620db2adb..e3b2e44f61 100644
--- a/src/cmd/compile/internal/inline/inl.go
+++ b/src/cmd/compile/internal/inline/inl.go
@@ -742,6 +742,9 @@ func InlineCalls(fn *ir.Func, profile *pgo.Profile) {
 	ir.CurFunc = fn
 	maxCost := int32(inlineMaxBudget)
 	if isBigFunc(fn) {
+		if base.Flag.LowerM > 1 {
+			fmt.Printf("%v: function %v considered 'big'; revising maxCost from %d to %d\n", ir.Line(fn), fn, maxCost, inlineBigFunctionMaxCost)
+		}
 		maxCost = inlineBigFunctionMaxCost
 	}
 	var inlCalls []*ir.InlinedCallExpr
diff --git a/test/inline_big.go b/test/inline_big.go
index 83672753f7..7dd1abdb6a 100644
--- a/test/inline_big.go
+++ b/test/inline_big.go
@@ -20,7 +20,7 @@ func medium(a []int) int { // ERROR "can inline medium with cost .* as:.*" "a do
 	return a[0] + a[1] + a[2] + a[3] + a[4] + a[5] + a[6] + a[7]
 }
 
-func f(a []int) int { // ERROR "cannot inline f:.*" "a does not escape"
+func f(a []int) int { // ERROR "cannot inline f:.*" "a does not escape" "function f considered 'big'"
 	// Add lots of nodes to f's body. We need >5000.
 	// See cmd/compile/internal/gc/inl.go:inlineBigFunction*
 	a[0] = 0