diff --git a/reactos/dll/win32/dbghelp/dbghelp_ros.diff b/reactos/dll/win32/dbghelp/dbghelp_ros.diff
index 6e26820208e..5e0c798716e 100644
--- a/reactos/dll/win32/dbghelp/dbghelp_ros.diff
+++ b/reactos/dll/win32/dbghelp/dbghelp_ros.diff
@@ -56,24 +56,9 @@ Index: stabs.c
  
  WINE_DEFAULT_DEBUG_CHANNEL(dbghelp_stabs);
  
-+UINT64 _strtoui64( const char *nptr, char **endptr, int base );
++_CRTIMP UINT64 _strtoui64( const char *nptr, char **endptr, int base );
++#define strtoull _strtoui64
 +
  #ifndef N_UNDF
  #define N_UNDF		0x00
  #endif
-@@ -468,13 +466,13 @@
-         break;
-     case '-':
-         prv->sign = -1;
--        prv->val = strtoull(++ptd->ptr, &last, 10);
-+        prv->val = _strtoui64(++ptd->ptr, &last, 10);
-         ptd->ptr = last;
-         break;
-     case '+':
-     default:    
-         prv->sign = 1;
--        prv->val = strtoull(ptd->ptr, &last, 10);
-+        prv->val = _strtoui64(ptd->ptr, &last, 10);
-         ptd->ptr = last;
-         break;
-     }
diff --git a/reactos/dll/win32/dbghelp/stabs.c b/reactos/dll/win32/dbghelp/stabs.c
index d68c9dc166b..d9af1b8023d 100644
--- a/reactos/dll/win32/dbghelp/stabs.c
+++ b/reactos/dll/win32/dbghelp/stabs.c
@@ -63,7 +63,8 @@
 
 WINE_DEFAULT_DEBUG_CHANNEL(dbghelp_stabs);
 
-UINT64 _strtoui64( const char *nptr, char **endptr, int base );
+_CRTIMP UINT64 _strtoui64( const char *nptr, char **endptr, int base );
+#define strtoull _strtoui64
 
 #ifndef N_UNDF
 #define N_UNDF		0x00
@@ -468,13 +469,13 @@ static int stabs_pts_read_range_value(struct ParseTypedefData* ptd, struct pts_r
         break;
     case '-':
         prv->sign = -1;
-        prv->val = _strtoui64(++ptd->ptr, &last, 10);
+        prv->val = strtoull(++ptd->ptr, &last, 10);
         ptd->ptr = last;
         break;
     case '+':
     default:    
         prv->sign = 1;
-        prv->val = _strtoui64(ptd->ptr, &last, 10);
+        prv->val = strtoull(ptd->ptr, &last, 10);
         ptd->ptr = last;
         break;
     }