diff --git a/src/cmd/compile/internal/gc/closure.go b/src/cmd/compile/internal/gc/closure.go
index 1c5c5eb1a2a..80c8d309afb 100644
--- a/src/cmd/compile/internal/gc/closure.go
+++ b/src/cmd/compile/internal/gc/closure.go
@@ -397,10 +397,42 @@ func transformclosure(xfunc *Node) {
 	lineno = lno
 }
 
+// hasemptycvars returns true iff closure func_ has an
+// empty list of captured vars. OXXX nodes don't count.
+func hasemptycvars(func_ *Node) bool {
+	for _, v := range func_.Func.Cvars.Slice() {
+		if v.Op == OXXX {
+			continue
+		}
+		return false
+	}
+	return true
+}
+
+// closuredebugruntimecheck applies boilerplate checks for debug flags
+// and compiling runtime
+func closuredebugruntimecheck(r *Node) {
+	if Debug_closure > 0 {
+		if r.Esc == EscHeap {
+			Warnl(r.Lineno, "heap closure, captured vars = %v", r.Func.Cvars)
+		} else {
+			Warnl(r.Lineno, "stack closure, captured vars = %v", r.Func.Cvars)
+		}
+	}
+	if compiling_runtime > 0 && r.Esc == EscHeap {
+		yyerrorl(r.Lineno, "heap-allocated closure, not allowed in runtime.")
+	}
+}
+
 func walkclosure(func_ *Node, init *Nodes) *Node {
 	// If no closure vars, don't bother wrapping.
-	if len(func_.Func.Cvars.Slice()) == 0 {
+	if hasemptycvars(func_) {
+		if Debug_closure > 0 {
+			Warnl(func_.Lineno, "closure converted to global")
+		}
 		return func_.Func.Closure.Func.Nname
+	} else {
+		closuredebugruntimecheck(func_)
 	}
 
 	// Create closure in the form of a composite literal.
diff --git a/src/cmd/compile/internal/gc/main.go b/src/cmd/compile/internal/gc/main.go
index fd18ae53121..a6eb1923103 100644
--- a/src/cmd/compile/internal/gc/main.go
+++ b/src/cmd/compile/internal/gc/main.go
@@ -31,10 +31,11 @@ var (
 )
 
 var (
-	Debug_append int
-	Debug_panic  int
-	Debug_slice  int
-	Debug_wb     int
+	Debug_append  int
+	Debug_closure int
+	Debug_panic   int
+	Debug_slice   int
+	Debug_wb      int
 )
 
 // Debug arguments.
@@ -46,6 +47,7 @@ var debugtab = []struct {
 	val  *int
 }{
 	{"append", &Debug_append},         // print information about append compilation
+	{"closure", &Debug_closure},       // print information about closure compilation
 	{"disablenil", &Disable_checknil}, // disable nil checks
 	{"gcprog", &Debug_gcprog},         // print dump of GC programs
 	{"nil", &Debug_checknil},          // print information about nil checks
diff --git a/src/cmd/compile/internal/gc/sinit.go b/src/cmd/compile/internal/gc/sinit.go
index e3bc46ac069..5144a2526e4 100644
--- a/src/cmd/compile/internal/gc/sinit.go
+++ b/src/cmd/compile/internal/gc/sinit.go
@@ -479,12 +479,17 @@ func staticassign(l *Node, r *Node, out *[]*Node) bool {
 		break
 
 	case OCLOSURE:
-		if len(r.Func.Cvars.Slice()) == 0 {
+		if hasemptycvars(r) {
+			if Debug_closure > 0 {
+				Warnl(r.Lineno, "closure converted to global")
+			}
 			// Closures with no captured variables are globals,
 			// so the assignment can be done at link time.
 			n := *l
 			gdata(&n, r.Func.Closure.Func.Nname, Widthptr)
 			return true
+		} else {
+			closuredebugruntimecheck(r)
 		}
 	}
 
diff --git a/test/fixedbugs/issue14999.go b/test/fixedbugs/issue14999.go
new file mode 100644
index 00000000000..c16d1ca5451
--- /dev/null
+++ b/test/fixedbugs/issue14999.go
@@ -0,0 +1,18 @@
+// errorcheck -+
+
+// Copyright 2016 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
+
+func f(x int) func(int) int {
+	return func(y int) int { return x + y } // ERROR "heap-allocated closure, not allowed in runtime."
+}
+
+func g(x int) func(int) int { // ERROR "x escapes to heap, not allowed in runtime."
+	return func(y int) int { // ERROR "heap-allocated closure, not allowed in runtime."
+		x += y
+		return x + y
+	}
+}