diff --git a/src/dmd/globals.d b/src/dmd/globals.d
index 2149b98b0fcc..3b5f15e37da6 100644
--- a/src/dmd/globals.d
+++ b/src/dmd/globals.d
@@ -504,6 +504,7 @@ enum MATCH : int
 {
     nomatch,   // no match
     convert,   // match with conversions
+    shared_,   // match with conversion to shared
     constant,  // match with conversion to const
     exact,     // exact match
 }
diff --git a/src/dmd/mtype.d b/src/dmd/mtype.d
index a589aa421b43..04f1e0ea7d26 100644
--- a/src/dmd/mtype.d
+++ b/src/dmd/mtype.d
@@ -79,7 +79,8 @@ bool MODimplicitConv(MOD modfrom, MOD modto) pure nothrow @nogc @safe
     case X(MODFlags.wild, MODFlags.const_):
     case X(MODFlags.wild, MODFlags.wildconst):
     case X(MODFlags.wildconst, MODFlags.const_):
-        return (modfrom & MODFlags.shared_) == (modto & MODFlags.shared_);
+        // Casting to shared is fine, but otherwise casting from shared is not.
+        return (modto & MODFlags.shared_) || !(modfrom & MODFlags.shared_);
 
     case X(MODFlags.immutable_, MODFlags.const_):
     case X(MODFlags.immutable_, MODFlags.wildconst):
@@ -116,6 +117,9 @@ MATCH MODmethodConv(MOD modfrom, MOD modto) pure nothrow @nogc @safe
     case X(MODFlags.shared_ | MODFlags.wildconst, MODFlags.shared_ | MODFlags.wild):
         return MATCH.constant;
 
+    case X(0,MODFlags.shared_):
+        return MATCH.shared_;
+
     default:
         return MATCH.nomatch;
     }