diff --git a/dyaml/node.d b/dyaml/node.d
index b38f182..7c12ed9 100644
--- a/dyaml/node.d
+++ b/dyaml/node.d
@@ -1323,7 +1323,7 @@ struct Node
         }
 
         //Get index of pair with key (or value, if value is true) matching index.
-        long findPair(T, bool value = false)(const ref T index) const
+        size_t findPair(T, bool value = false)(const ref T index) const
         {
             const pairs = value_.get!(const Pair[])();
             const(Node)* node;
diff --git a/dyaml/reader.d b/dyaml/reader.d
index 21fb407..17cda41 100644
--- a/dyaml/reader.d
+++ b/dyaml/reader.d
@@ -312,7 +312,7 @@ final class Reader
         }
 
         //Handle an exception thrown in loadChars method of any Reader.
-        void handleLoadCharsException(Exception e, size_t oldPosition)
+        void handleLoadCharsException(Exception e, ulong oldPosition)
         {
             try{throw e;}
             catch(UtfException e)
@@ -572,7 +572,7 @@ struct UTFBlockDecoder(size_t bufferSize_) if (bufferSize_ % 2 == 0)
             {
                 for(long end = max - 1; end >= 0; --end)
                 {
-                    const s = utf8Stride[buffer[end]];
+                    const s = utf8Stride[buffer[cast(size_t)end]];
                     if(s != 0xFF)
                     {
                         //If stride goes beyond end of the buffer (max), return end.