diff --git a/src/runtime/symtab.go b/src/runtime/symtab.go
index 98b5f900e6..d69f610ebb 100644
--- a/src/runtime/symtab.go
+++ b/src/runtime/symtab.go
@@ -222,6 +222,15 @@ type modulehash struct {
 	runtimehash  *string
 }
 
+// pinnedTypemaps are the map[typeOff]*_type from the moduledata objects.
+//
+// These typemap objects are allocated at run time on the heap, but the
+// only direct reference to them is in the moduledata, created by the
+// linker and marked SNOPTRDATA so it is ignored by the GC.
+//
+// To make sure the map isn't collected, we keep a second reference here.
+var pinnedTypemaps []map[typeOff]*_type
+
 var firstmoduledata moduledata  // linker symbol
 var lastmoduledatap *moduledata // linker symbol
 
diff --git a/src/runtime/type.go b/src/runtime/type.go
index 7f7849d5a0..cacf880e9e 100644
--- a/src/runtime/type.go
+++ b/src/runtime/type.go
@@ -497,7 +497,9 @@ func typelinksinit() {
 			// If any of this module's typelinks match a type from a
 			// prior module, prefer that prior type by adding the offset
 			// to this module's typemap.
-			md.typemap = make(map[typeOff]*_type, len(md.typelinks))
+			tm := make(map[typeOff]*_type, len(md.typelinks))
+			pinnedTypemaps = append(pinnedTypemaps, tm)
+			md.typemap = tm
 			for _, tl := range md.typelinks {
 				t := (*_type)(unsafe.Pointer(md.types + uintptr(tl)))
 				for _, candidate := range typehash[t.hash] {