diff --git a/src/cmd/compile/internal/gc/const.go b/src/cmd/compile/internal/gc/const.go
index 9f5afadd70..afcdb95443 100644
--- a/src/cmd/compile/internal/gc/const.go
+++ b/src/cmd/compile/internal/gc/const.go
@@ -584,6 +584,14 @@ func Isconst(n *Node, ct Ctype) bool {
 
 // evconst rewrites constant expressions into OLITERAL nodes.
 func evconst(n *Node) {
+	if !n.isGoConst() {
+		// Avoid constant evaluation of things that aren't actually constants
+		// according to the spec. See issue 24760.
+		// The SSA backend has a more robust optimizer that will catch
+		// all of these weird cases (like uintptr(unsafe.Pointer(uintptr(1)))).
+		return
+	}
+
 	nl, nr := n.Left, n.Right
 
 	// Pick off just the opcodes that can be constant evaluated.
@@ -1268,7 +1276,7 @@ func nonnegintconst(n *Node) int64 {
 //
 // Expressions derived from nil, like string([]byte(nil)), while they
 // may be known at compile time, are not Go language constants.
-// Only called for expressions known to evaluated to compile-time
+// Only called for expressions known to evaluate to compile-time
 // constants.
 func (n *Node) isGoConst() bool {
 	if n.Orig != nil {
@@ -1277,7 +1285,6 @@ func (n *Node) isGoConst() bool {
 
 	switch n.Op {
 	case OADD,
-		OADDSTR,
 		OAND,
 		OANDAND,
 		OANDNOT,
@@ -1301,13 +1308,25 @@ func (n *Node) isGoConst() bool {
 		OSUB,
 		OXOR,
 		OIOTA,
-		OCOMPLEX,
 		OREAL,
 		OIMAG:
 		if n.Left.isGoConst() && (n.Right == nil || n.Right.isGoConst()) {
 			return true
 		}
 
+	case OCOMPLEX:
+		if n.List.Len() == 0 && n.Left.isGoConst() && n.Right.isGoConst() {
+			return true
+		}
+
+	case OADDSTR:
+		for _, n1 := range n.List.Slice() {
+			if !n1.isGoConst() {
+				return false
+			}
+		}
+		return true
+
 	case OCONV:
 		if okforconst[n.Type.Etype] && n.Left.isGoConst() {
 			return true
diff --git a/src/cmd/compile/internal/gc/fmt.go b/src/cmd/compile/internal/gc/fmt.go
index 36f7545b3c..f128872dbb 100644
--- a/src/cmd/compile/internal/gc/fmt.go
+++ b/src/cmd/compile/internal/gc/fmt.go
@@ -1400,9 +1400,16 @@ func (n *Node) exprfmt(s fmt.State, prec int, mode fmtMode) {
 		}
 		mode.Fprintf(s, "sliceheader{%v,%v,%v}", n.Left, n.List.First(), n.List.Second())
 
-	case OCOPY, OCOMPLEX:
+	case OCOPY:
 		mode.Fprintf(s, "%#v(%v, %v)", n.Op, n.Left, n.Right)
 
+	case OCOMPLEX:
+		if n.List.Len() == 1 {
+			mode.Fprintf(s, "%#v(%v)", n.Op, n.List.First())
+		} else {
+			mode.Fprintf(s, "%#v(%v, %v)", n.Op, n.Left, n.Right)
+		}
+
 	case OCONV,
 		OCONVIFACE,
 		OCONVNOP,
diff --git a/src/cmd/compile/internal/gc/syntax.go b/src/cmd/compile/internal/gc/syntax.go
index 9ecea8a4c5..0be52f1271 100644
--- a/src/cmd/compile/internal/gc/syntax.go
+++ b/src/cmd/compile/internal/gc/syntax.go
@@ -692,7 +692,7 @@ const (
 	OIOTA        // iota
 	OREAL        // real(Left)
 	OIMAG        // imag(Left)
-	OCOMPLEX     // complex(Left, Right)
+	OCOMPLEX     // complex(Left, Right) or complex(List[0]) where List[0] is a 2-result function call
 	OALIGNOF     // unsafe.Alignof(Left)
 	OOFFSETOF    // unsafe.Offsetof(Left)
 	OSIZEOF      // unsafe.Sizeof(Left)
diff --git a/test/fixedbugs/issue17038.go b/test/fixedbugs/issue17038.go
index 1b65ffc1f0..e07a4b22ce 100644
--- a/test/fixedbugs/issue17038.go
+++ b/test/fixedbugs/issue17038.go
@@ -6,4 +6,4 @@
 
 package main
 
-const A = complex(0()) // ERROR "cannot call non-function"
+const A = complex(0()) // ERROR "cannot call non-function" "const initializer .* is not a constant"
diff --git a/test/fixedbugs/issue24760.go b/test/fixedbugs/issue24760.go
new file mode 100644
index 0000000000..cd6f124517
--- /dev/null
+++ b/test/fixedbugs/issue24760.go
@@ -0,0 +1,12 @@
+// compile
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package p
+
+import "unsafe"
+
+var _ = string([]byte(nil))[0]
+var _ = uintptr(unsafe.Pointer(uintptr(1))) << 100