diff --git a/dlls/msvcp60/locale.c b/dlls/msvcp60/locale.c
index bbeb5a50c04..f3500142f69 100644
--- a/dlls/msvcp60/locale.c
+++ b/dlls/msvcp60/locale.c
@@ -3970,7 +3970,7 @@ static int num_get__Getffld(const num_get *this, char *dest, istreambuf_iterator
 
     numpunct_wchar_grouping(numpunct, &grouping_bstr);
     grouping = basic_string_char_c_str(&grouping_bstr);
-    sep = grouping ? numpunct_wchar_thousands_sep(numpunct) : (wchar_t)0;
+    sep = grouping[0] ? numpunct_wchar_thousands_sep(numpunct) : (wchar_t)0;
 
     if(sep)
         basic_string_char_ctor(&groups_found);
@@ -4124,7 +4124,7 @@ static int num_get__Getifld(const num_get *this, char *dest, istreambuf_iterator
 
     numpunct_wchar_grouping(numpunct, &grouping_bstr);
     grouping = basic_string_char_c_str(&grouping_bstr);
-    sep = grouping ? numpunct_wchar_thousands_sep(numpunct) : '\0';
+    sep = grouping[0] ? numpunct_wchar_thousands_sep(numpunct) : '\0';
 
     basefield = fmtflags & FMTFLAG_basefield;
     if(basefield == FMTFLAG_oct)
@@ -5034,7 +5034,7 @@ static int num_get_char__Getffld(const num_get *this, char *dest, istreambuf_ite
 
     numpunct_char_grouping(numpunct, &grouping_bstr);
     grouping = basic_string_char_c_str(&grouping_bstr);
-    sep = grouping ? numpunct_char_thousands_sep(numpunct) : '\0';
+    sep = grouping[0] ? numpunct_char_thousands_sep(numpunct) : '\0';
 
     if(sep)
         basic_string_char_ctor(&groups_found);
@@ -5186,7 +5186,7 @@ static int num_get_char__Getifld(const num_get *this, char *dest, istreambuf_ite
 
     numpunct_char_grouping(numpunct, &grouping_bstr);
     grouping = basic_string_char_c_str(&grouping_bstr);
-    sep = grouping ? numpunct_char_thousands_sep(numpunct) : '\0';
+    sep = grouping[0] ? numpunct_char_thousands_sep(numpunct) : '\0';
 
     basefield = fmtflags & FMTFLAG_basefield;
     if(basefield == FMTFLAG_oct)
@@ -5949,7 +5949,7 @@ static ostreambuf_iterator_char* num_put_char_fput(const num_put *this, ostreamb
     /* Add separators to number */
     numpunct_char_grouping(numpunct, &grouping_bstr);
     grouping = basic_string_char_c_str(&grouping_bstr);
-    sep = grouping ? numpunct_char_thousands_sep(numpunct) : '\0';
+    sep = grouping[0] ? numpunct_char_thousands_sep(numpunct) : '\0';
 
     for(; p>buf && sep && grouping[cur_group]!=CHAR_MAX; p--) {
         group_size++;
@@ -6032,7 +6032,7 @@ static ostreambuf_iterator_char* num_put_char__Iput(const num_put *this, ostream
     /* Add separators to number */
     numpunct_char_grouping(numpunct, &grouping_bstr);
     grouping = basic_string_char_c_str(&grouping_bstr);
-    sep = grouping ? numpunct_char_thousands_sep(numpunct) : '\0';
+    sep = grouping[0] ? numpunct_char_thousands_sep(numpunct) : '\0';
 
     for(p=buf+count-1; p>buf && sep && grouping[cur_group]!=CHAR_MAX; p--) {
         group_size++;
diff --git a/dlls/msvcp60/string.c b/dlls/msvcp60/string.c
index ed4391c7cc6..69917dca601 100644
--- a/dlls/msvcp60/string.c
+++ b/dlls/msvcp60/string.c
@@ -1666,7 +1666,7 @@ DEFINE_THISCALL_WRAPPER(basic_string_char_c_str, 4)
 const char* __thiscall basic_string_char_c_str(const basic_string_char *this)
 {
     TRACE("%p\n", this);
-    return this->ptr;
+    return this->ptr ? this->ptr : basic_string_char__Nullstr();
 }
 
 /* ?size@?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@QBEIXZ */
@@ -3376,7 +3376,7 @@ DEFINE_THISCALL_WRAPPER(basic_string_wchar_c_str, 4)
 const wchar_t* __thiscall basic_string_wchar_c_str(const basic_string_wchar *this)
 {
     TRACE("%p\n", this);
-    return this->ptr;
+    return this->ptr ? this->ptr : basic_string_wchar__Nullstr();
 }
 
 /* ?size@?$basic_string@GU?$char_traits@G@std@@V?$allocator@G@2@@std@@QBEIXZ */