diff --git a/dlls/dbghelp/module.c b/dlls/dbghelp/module.c
index 9df02dfa05f..c6c9d5eb199 100644
--- a/dlls/dbghelp/module.c
+++ b/dlls/dbghelp/module.c
@@ -461,7 +461,7 @@ enum module_type module_get_type_by_name(const WCHAR* name)
     {
         int i = len;
 
-        while (i && isdigit(name[i - 1])) i--;
+        while (i && name[i - 1] >= '0' && name[i - 1] <= '9') i--;
 
         if (i && name[i - 1] == '.')
             len = i - 1;