diff --git a/gcc/cp/contracts.cc b/gcc/cp/contracts.cc
index 39f0487ea36..4d2849a289a 100644
--- a/gcc/cp/contracts.cc
+++ b/gcc/cp/contracts.cc
@@ -145,6 +145,7 @@ along with GCC; see the file COPYING3.  If not see
 #include "print-tree.h"
 #include "stor-layout.h"
 #include "intl.h"
+#include "cgraph.h"
 
 const int max_custom_roles = 32;
 static contract_role contract_build_roles[max_custom_roles] = {
@@ -1458,9 +1459,14 @@ build_contract_condition_function (tree fndecl, bool pre)
       DECL_WEAK (fn) = false;
       DECL_COMDAT (fn) = false;
 
-      /* We haven't set the comdat group on the guarded function yet, we'll add
-	 this to the same group in comdat_linkage later.  */
-      gcc_assert (!DECL_ONE_ONLY (fndecl));
+      /* We may not have set the comdat group on the guarded function yet.
+	 If we haven't, we'll add this to the same group in comdat_linkage
+	 later.  Otherwise, add it to the same comdat group now.  */
+      if (DECL_ONE_ONLY (fndecl))
+	{
+	  symtab_node *n = symtab_node::get (fndecl);
+	  cgraph_node::get_create (fn)->add_to_same_comdat_group (n);
+	}
 
       DECL_INTERFACE_KNOWN (fn) = true;
     }
diff --git a/gcc/testsuite/g++.dg/contracts/pr116490.C b/gcc/testsuite/g++.dg/contracts/pr116490.C
new file mode 100644
index 00000000000..e3a5d77bafd
--- /dev/null
+++ b/gcc/testsuite/g++.dg/contracts/pr116490.C
@@ -0,0 +1,56 @@
+// ICE in explicit instantiation of a function with contracts
+// { dg-do run }
+// { dg-options "-std=c++20 -fcontracts -fcontract-continuation-mode=on" }
+
+template<class T>
+void foo(T t)
+[[pre : t == 9 ]] {
+}
+
+template void foo<int>(int i);
+
+
+template<class T>
+struct templateS
+{
+  void fooS(T t)
+  [[pre : t == 9 ]] {
+  }
+};
+
+template struct templateS<int>;
+
+
+struct S {
+
+  template<class T>
+  void fooS(T t)
+  [[pre : t == 9 ]] {
+  }
+
+  template<class T>
+  static void fooStatic(T t)
+  [[pre : t == 9 ]] {
+  }
+};
+
+template void S::fooS<int>(int i);
+
+template void S::fooStatic<int>(int i);
+
+int main()
+{
+   foo(3);
+
+   templateS<int> ts;
+   ts.fooS(3);
+
+   S s;
+   s.fooS(3);
+   S::fooStatic(3);
+}
+
+// { dg-output "contract violation in function foo<int> at .* t == 9.*(\n|\r\n|\r)" }
+// { dg-output "contract violation in function templateS<int>::fooS at .* t == 9.*(\n|\r\n|\r)" }
+// { dg-output "contract violation in function S::fooS<int> at .* t == 9.*(\n|\r\n|\r)" }
+// { dg-output "contract violation in function S::fooStatic<int> at .* t == 9.*(\n|\r\n|\r)" }