diff --git a/src/vim9compile.c b/src/vim9compile.c
index 2a305ee..8e07968 100644
--- a/src/vim9compile.c
+++ b/src/vim9compile.c
@@ -7336,6 +7336,8 @@
     dfunc->df_idx = def_functions.ga_len;
     ufunc->uf_dfunc_idx = dfunc->df_idx;
     dfunc->df_ufunc = ufunc;
+    dfunc->df_name = vim_strsave(ufunc->uf_name);
+    ++dfunc->df_refcount;
     ++def_functions.ga_len;
     return OK;
 }
@@ -7928,6 +7930,7 @@
 	for (idx = 0; idx < instr->ga_len; ++idx)
 	    delete_instr(((isn_T *)instr->ga_data) + idx);
 	ga_clear(instr);
+	VIM_CLEAR(dfunc->df_name);
 
 	// If using the last entry in the table and it was added above, we
 	// might as well remove it.
@@ -8102,9 +8105,7 @@
 
 		if (ufunc != NULL)
 		{
-		    // Clear uf_dfunc_idx so that the function is deleted.
-		    clear_def_function(ufunc);
-		    ufunc->uf_dfunc_idx = 0;
+		    unlink_def_function(ufunc);
 		    func_ptr_unref(ufunc);
 		}
 
@@ -8206,7 +8207,7 @@
 }
 
 /*
- * Free all instructions for "dfunc".
+ * Free all instructions for "dfunc" except df_name.
  */
     static void
 delete_def_function_contents(dfunc_T *dfunc)
@@ -8227,31 +8228,39 @@
 
 /*
  * When a user function is deleted, clear the contents of any associated def
- * function.  The position in def_functions can be re-used.
+ * function, unless another user function still uses it.
+ * The position in def_functions can be re-used.
  */
     void
-clear_def_function(ufunc_T *ufunc)
+unlink_def_function(ufunc_T *ufunc)
 {
     if (ufunc->uf_dfunc_idx > 0)
     {
 	dfunc_T *dfunc = ((dfunc_T *)def_functions.ga_data)
 							 + ufunc->uf_dfunc_idx;
 
-	delete_def_function_contents(dfunc);
+	if (--dfunc->df_refcount <= 0)
+	    delete_def_function_contents(dfunc);
 	ufunc->uf_def_status = UF_NOT_COMPILED;
+	ufunc->uf_dfunc_idx = 0;
+	if (dfunc->df_ufunc == ufunc)
+	    dfunc->df_ufunc = NULL;
     }
 }
 
 /*
- * Used when a user function is about to be deleted: remove the pointer to it.
- * The entry in def_functions is then unused.
+ * Used when a user function refers to an existing dfunc.
  */
     void
-unlink_def_function(ufunc_T *ufunc)
+link_def_function(ufunc_T *ufunc)
 {
-    dfunc_T *dfunc = ((dfunc_T *)def_functions.ga_data) + ufunc->uf_dfunc_idx;
+    if (ufunc->uf_dfunc_idx > 0)
+    {
+	dfunc_T *dfunc = ((dfunc_T *)def_functions.ga_data)
+							 + ufunc->uf_dfunc_idx;
 
-    dfunc->df_ufunc = NULL;
+	++dfunc->df_refcount;
+    }
 }
 
 #if defined(EXITFREE) || defined(PROTO)
@@ -8268,6 +8277,7 @@
 	dfunc_T *dfunc = ((dfunc_T *)def_functions.ga_data) + idx;
 
 	delete_def_function_contents(dfunc);
+	vim_free(dfunc->df_name);
     }
 
     ga_clear(&def_functions);