diff --git a/ChangeLog b/ChangeLog
index 00e107e35d..54b1df5221 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Sep 16 13:39:10 2009  Marc-Andre Lafortune  <ruby-core@marc-andre.ca>
+
+	* lib/matrix.rb (determinant): Bug fix where determinant failed on
+	  some matrices [ruby-core:23597]
+
 Wed Sep 16 13:30:20 2009  Marc-Andre Lafortune  <ruby-core@marc-andre.ca>
 
 	* lib/matrix.rb:  trivial optimizations
diff --git a/lib/matrix.rb b/lib/matrix.rb
index 2d5dfea424..e4a81ea013 100644
--- a/lib/matrix.rb
+++ b/lib/matrix.rb
@@ -669,7 +669,7 @@ class Matrix
       if (akk = a[k][k]) == 0
         i = k
         loop do
-          return 0 if (ii += 1) > size
+          return 0 if (i += 1) > size
           break unless a[i][k] == 0
         end
         a[i], a[k] = a[k], a[i]