diff --git a/src/Makefile.am b/src/Makefile.am
index 54f07269..65471a42 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -47,7 +47,7 @@ liblolcore_headers = \
     lol/math/transform.h \
     \
     lol/algorithm/all.h \
-    lol/algorithm/sort.h lol/algorithm/portal.h lol/algorithm/aabb_tree.h \
+    lol/algorithm/sort.h lol/algorithm/portal.h lol/algorithm/aabb_tree.h lol/algorithm/avl_tree.h \
     \
     lol/sys/all.h \
     lol/sys/init.h lol/sys/file.h lol/sys/thread.h lol/sys/timer.h \
diff --git a/src/lol/algorithm/all.h b/src/lol/algorithm/all.h
index dec445fc..2f7e1268 100644
--- a/src/lol/algorithm/all.h
+++ b/src/lol/algorithm/all.h
@@ -12,5 +12,6 @@
 
 #include <lol/algorithm/sort.h>
 #include <lol/algorithm/aabb_tree.h>
+#include <lol/algorithm/avl_tree.h>
 #include <lol/algorithm/portal.h>
 
diff --git a/src/lol/base/avl_tree.h b/src/lol/algorithm/avl_tree.h
similarity index 93%
rename from src/lol/base/avl_tree.h
rename to src/lol/algorithm/avl_tree.h
index 6fafa636..8bf47848 100644
--- a/src/lol/base/avl_tree.h
+++ b/src/lol/algorithm/avl_tree.h
@@ -56,9 +56,9 @@ private:
             m_key(key),
             m_value(value),
             m_lo(0),
-            m_hi(0)
+            m_hi(0),
             m_stairs_lo(0),
-            m_stairs_hi(0),
+            m_stairs_hi(0)
         {
         }
 
@@ -89,9 +89,9 @@ private:
         int path_update_balance(K const & key)
         {
             if (key < this->m_key)
-                this->m_stairs_lo = lol::max(this->m_lo->path_update_balance(node), this->m_stairs_lo);
+                this->m_stairs_lo = lol::max(this->m_lo->path_update_balance(key), this->m_stairs_lo);
             else if (this->m_key < key)
-                this->m_stairs_hi = lol::max(this->m_hi->path_update_balance(node), this->m_stairs_hi);
+                this->m_stairs_hi = lol::max(this->m_hi->path_update_balance(key), this->m_stairs_hi);
 
             return lol::max(this->m_stairs_lo, this->m_stairs_hi) + 1;
         }
@@ -104,7 +104,7 @@ private:
                 if (node)
                 {
                     this->m_lo = node;
-                    --this->m_lo;
+                    --this->m_stairs_lo;
                 }
             }
             else if (this->m_key < key)
@@ -113,7 +113,7 @@ private:
                 if (node)
                 {
                     this->m_hi = node;
-                    --this->m_hi;
+                    --this->m_stairs_hi;
                 }
             }
 
@@ -142,7 +142,7 @@ private:
                 this->m_lo = lo_hi;
 
                 this->compute_balance();
-                lo_hi->compute_balance();
+                lo->compute_balance();
 
                 return lo;
             }
@@ -155,9 +155,9 @@ private:
                 this->m_hi = hi_lo;
 
                 this->compute_balance();
-                hi_lo->compute_balance();
+                hi->compute_balance();
 
-                return lo;
+                return hi;
             }
 
             return 0;
diff --git a/src/t/Makefile.am b/src/t/Makefile.am
index 273b79af..264860a6 100644
--- a/src/t/Makefile.am
+++ b/src/t/Makefile.am
@@ -7,9 +7,14 @@ TESTS = $(testsuite)
 
 # Conditionally built for now because of STLport issues
 if !USE_ANDROID
-testsuite = test-base test-math test-sys test-image test-entity
+testsuite = test-algorithm test-base test-math test-sys test-image test-entity
 endif
 
+test_algorithm_SOURCES = test-common.cpp \
+    algorithm/avl_tree.cpp
+test_algorithm_CPPFLAGS = $(AM_CPPFLAGS) -I$(top_srcdir)/tools/lolunit
+test_algorithm_DEPENDENCIES = @LOL_DEPS@
+
 test_base_SOURCES = test-common.cpp \
     base/array.cpp base/enum.cpp base/map.cpp base/string.cpp \
     base/types.cpp