diff --git a/src/runtime/internal/startlinetest/func_amd64.go b/src/runtime/internal/startlinetest/func_amd64.go
index 6cd9a3f417..ab7063d615 100644
--- a/src/runtime/internal/startlinetest/func_amd64.go
+++ b/src/runtime/internal/startlinetest/func_amd64.go
@@ -8,3 +8,6 @@ package startlinetest
 // Defined in func_amd64.s, this is a trivial assembly function that calls
 // runtime_test.callerStartLine.
 func AsmFunc() int
+
+// Provided by runtime_test.
+var CallerStartLine func(bool) int
diff --git a/src/runtime/internal/startlinetest/func_amd64.s b/src/runtime/internal/startlinetest/func_amd64.s
index ace5b34e70..96982bedab 100644
--- a/src/runtime/internal/startlinetest/func_amd64.s
+++ b/src/runtime/internal/startlinetest/func_amd64.s
@@ -23,5 +23,6 @@
 TEXT	·AsmFunc<ABIInternal>(SB),NOSPLIT,$8-0
 	NO_LOCAL_POINTERS
 	MOVQ	$0, AX // wantInlined
-	CALL    runtime_test·callerStartLine<ABIInternal>(SB)
+	MOVQ	·CallerStartLine(SB), DX
+	CALL	(DX)
 	RET
diff --git a/src/runtime/start_line_amd64_test.go b/src/runtime/start_line_amd64_test.go
index 57001e71de..305ed0b126 100644
--- a/src/runtime/start_line_amd64_test.go
+++ b/src/runtime/start_line_amd64_test.go
@@ -13,6 +13,8 @@ import (
 // is only tested on amd64 to avoid the need for a proliferation of per-arch
 // copies of this function.
 func TestStartLineAsm(t *testing.T) {
+	startlinetest.CallerStartLine = callerStartLine
+
 	const wantLine = 23
 	got := startlinetest.AsmFunc()
 	if got != wantLine {