diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 39232b5e67f..e1764743597 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -1985,6 +1985,17 @@ reregister_specialization (tree spec, tree tinfo, tree new_spec)
       gcc_assert (entry->spec == spec || entry->spec == new_spec);
       gcc_assert (new_spec != NULL_TREE);
       entry->spec = new_spec;
+
+      /* We need to also remove the old specialisation from
+	 DECL_TEMPLATE_INSTANTIATIONS if it was placed there.  */
+      for (tree *inst = &DECL_TEMPLATE_INSTANTIATIONS (elt.tmpl);
+	   *inst; inst = &TREE_CHAIN (*inst))
+	if (TREE_VALUE (*inst) == spec)
+	  {
+	    *inst = TREE_CHAIN (*inst);
+	    break;
+	  }
+
       return 1;
     }
 
diff --git a/gcc/testsuite/g++.dg/modules/pr118807.C b/gcc/testsuite/g++.dg/modules/pr118807.C
new file mode 100644
index 00000000000..a97afb92699
--- /dev/null
+++ b/gcc/testsuite/g++.dg/modules/pr118807.C
@@ -0,0 +1,11 @@
+// PR c++/118807
+// { dg-additional-options "-fmodules --param=ggc-min-expand=0 --param=ggc-min-heapsize=0 -Wno-global-module" }
+
+module;
+template <typename> class basic_streambuf;
+template <typename> struct basic_streambuf {
+  friend void __istream_extract();
+};
+template class basic_streambuf<char>;
+template class basic_streambuf<wchar_t>;
+export module M;