diff --git a/Contrib/ExDLL/plugin.c b/Contrib/ExDLL/plugin.c
index 24b9e3fe..0a55af19 100644
--- a/Contrib/ExDLL/plugin.c
+++ b/Contrib/ExDLL/plugin.c
@@ -99,6 +99,21 @@ int NSISCALL myatoi(const char *s)
   return v;
 }
 
+unsigned NSISCALL myatou(const char *s)
+{
+  unsigned int v=0;
+
+  for (;;)
+  {
+    unsigned int c=*s++;
+    if (c >= '0' && c <= '9') c-='0';
+    else break;
+    v*=10;
+    v+=c;
+  }
+  return v;
+}
+
 int NSISCALL myatoi_or(const char *s)
 {
   int v=0;
diff --git a/Contrib/ExDLL/plugin.h b/Contrib/ExDLL/plugin.h
index 29e1ab84..63b8b846 100644
--- a/Contrib/ExDLL/plugin.h
+++ b/Contrib/ExDLL/plugin.h
@@ -60,6 +60,7 @@ int NSISCALL popstringn(char *str, int maxlen); // with length limit, pass 0 for
 int NSISCALL popint(); // pops an integer
 int NSISCALL popint_or(); // with support for or'ing (2|4|8)
 int NSISCALL myatoi(const char *s); // converts a string to an integer
+unsigned NSISCALL myatou(const char *s); // converts a string to an unsigned integer, decimal only
 int NSISCALL myatoi_or(const char *s); // with support for or'ing (2|4|8)
 void NSISCALL pushstring(const char *str);
 void NSISCALL pushint(int value);