diff --git a/Compiler/PCU/PCUReader.cs b/Compiler/PCU/PCUReader.cs
index 65e73c023..e0c9bb159 100644
--- a/Compiler/PCU/PCUReader.cs
+++ b/Compiler/PCU/PCUReader.cs
@@ -790,24 +790,26 @@ namespace PascalABCCompiler.PCU
                 param_types[i] = FindSpecTypeByHandle(pcu_file.dotnet_names[off].addit[i].offset);
             }
             MethodInfo mi = null;
-                if (pcu_file.dotnet_names[off].name != "op_Explicit")
+            if (pcu_file.dotnet_names[off].name != "op_Explicit")
+            {
+                //mi = t.GetMethod(pcu_file.dotnet_names[off].name, param_types);
+                List<MemberInfo> mis = NetHelper.NetHelper.GetMembers(t, pcu_file.dotnet_names[off].name);
+                mi = ChooseMethod(t, mis, param_types);
+            }
+            else
+            {
+                MethodInfo[] mis = t.GetMethods();
+                foreach (MethodInfo mi2 in mis)
+                    if (mi2.Name == "op_Explicit" && mi2.GetParameters()[0].ParameterType == param_types[0].t && mi2.ReturnType == param_types[1].t) mi = mi2;
+                if (mi == null)
                 {
-                    //mi = t.GetMethod(pcu_file.dotnet_names[off].name, param_types);
-                    List<MemberInfo> mis = NetHelper.NetHelper.GetMembers(t, pcu_file.dotnet_names[off].name);
-                    mi = ChooseMethod(t, mis, param_types);
-                }
-                else
-                {
-                    MethodInfo[] mis = t.GetMethods();
-                    foreach (MethodInfo mi2 in mis)
-                        if (mi2.Name == "op_Explicit" && mi2.GetParameters()[0].ParameterType == param_types[0].t && mi2.ReturnType == param_types[1].t) mi = mi2;
-                    if (mi == null)
-                    {
-                        List<MemberInfo> mis2 = NetHelper.NetHelper.GetMembers(t, pcu_file.dotnet_names[off].name);
-                        mi = ChooseMethod(t, mis2, param_types);
-                        //mi = t.GetMethod(pcu_file.dotnet_names[off].name, new Type[1] { param_types[0].t });
-                    }
+                    List<MemberInfo> mis2 = NetHelper.NetHelper.GetMembers(t, pcu_file.dotnet_names[off].name);
+                    mi = ChooseMethod(t, mis2, param_types);
+                    //mi = t.GetMethod(pcu_file.dotnet_names[off].name, new Type[1] { param_types[0].t });
                 }
+            }
+            if (mi == null)
+                throw new Exception(pcu_file.dotnet_names[off].name+" "+t.FullName);
             dot_net_cache[off] = mi;
             return mi;
         }
diff --git a/TestSuite/defaultparams1.pas b/TestSuite/defaultparams1.pas
index 8997a5a89..f9ebe41d7 100644
--- a/TestSuite/defaultparams1.pas
+++ b/TestSuite/defaultparams1.pas
@@ -13,6 +13,21 @@ begin
   Result := a;
 end;
 
+function ff(delim: string := ' '): string;
+begin
+  Result := 'abc';
+end;
+
+procedure tt(str: string);
+begin
+  assert(str = 'abc');
+end;
+
+procedure tt(i: integer);
+begin
+  raise new Exception;
+end;
+
 begin
 assert(test(2)=3);
 assert(test(2,4)=4);
@@ -24,4 +39,5 @@ var s := 'abcd';
 assert(s.test=6);
 var k := s.test;
 assert(k = 6);
+tt(ff);
 end.
\ No newline at end of file
diff --git a/bin/Lib/PABCSystem.pas b/bin/Lib/PABCSystem.pas
index e57763bfb..073193d60 100644
--- a/bin/Lib/PABCSystem.pas
+++ b/bin/Lib/PABCSystem.pas
@@ -2267,9 +2267,9 @@ end;
 function FormatStr(obj: object): string;
 begin
   if (obj.GetType = typeof(char)) or (obj.GetType = typeof(string)) then
-    Result := '''' + string.Format(System.Globalization.NumberFormatInfo.InvariantInfo, '{0}', obj) + ''''
+    Result := '''' + string.Format(System.Globalization.NumberFormatInfo.InvariantInfo, '{0}', new object[](obj)) + ''''
   else
-    Result := string.Format(System.Globalization.NumberFormatInfo.InvariantInfo, '{0}', obj)
+    Result := string.Format(System.Globalization.NumberFormatInfo.InvariantInfo, '{0}', new object[](obj))
 end;
 
 function TypedSet.ToString: string;