diff --git a/configure.ac b/configure.ac
index 2b4964c..567c844 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,7 +1,7 @@
 dnl Process this file with autoconf to produce a configure script.
 AC_INIT
 AC_CONFIG_SRCDIR([Makefile.am])
-AM_INIT_AUTOMAKE(cmph, 1.0)
+AM_INIT_AUTOMAKE(cmph, 2.0)
 AC_CONFIG_HEADERS([config.h])
 AC_CONFIG_MACRO_DIR([m4])
 
@@ -34,7 +34,7 @@ LDFLAGS="$LIBM $LDFLAGS"
 CFLAGS="-Wall"
 
 AC_PROG_CXX
-CXXFLAGS="-Wall -Wno-unused-function -DNDEBUG -O3 -fomit-frame-pointer $CXXFLAGS"
+CXXFLAGS="-Werror -Wall -Wno-unused-function -DNDEBUG -O3 -fomit-frame-pointer $CXXFLAGS"
 AC_ENABLE_CXXMPH
 if test x$cxxmph = xtrue; then
   AC_COMPILE_STDCXX_0X
diff --git a/cxxmph/map_tester.h b/cxxmph/map_tester.h
index ea2b358..d3e5972 100644
--- a/cxxmph/map_tester.h
+++ b/cxxmph/map_tester.h
@@ -11,6 +11,7 @@
 
 namespace cxxmph {
 
+using namespace cxxmph;
 using namespace std;
 
 template <template<typename...> class map_type>
@@ -24,8 +25,9 @@ struct MapTester {
   static bool large_insert() {
     map_type<int64_t, int64_t> m;
     // Start counting from 1 to not touch default constructed value bugs
-    for (int i = 1; i < 12 * 256 * 256; ++i) m.insert(make_pair(i, i));
-    return m.size() == 12 * 256 * 256 - 1;
+    int nkeys = 12 * 256 * 256;
+    for (int i = 1; i < nkeys; ++i) m.insert(make_pair(i, i));
+    return static_cast<int>(m.size()) == nkeys - 0;
   }
   static bool small_search() {
     map_type<int64_t, int64_t> m;
@@ -54,7 +56,7 @@ struct MapTester {
     int nkeys = 10 * 1000;
     vector<string> keys;
     for (int i = 0; i < nkeys; ++i) {
-      keys.push_back(cxxmph::format("%v", i));
+      keys.push_back(format("%v", i));
     }
     map_type<string, int64_t> m;
     for (int i = 0; i < nkeys; ++i) m.insert(make_pair(keys[i], i));
@@ -65,6 +67,42 @@ struct MapTester {
     }
     return true;
   }
+  static bool rehash_zero() {
+    map_type<int64_t, int64_t> m;
+    m.rehash(0);
+    return m.size() == 0;
+  }
+  static bool rehash_size() {
+    map_type<int64_t, int64_t> m;
+    int nkeys = 10 * 1000;
+    for (int i = 0; i < nkeys; ++i) { m.insert(make_pair(i, i)); }
+    m.rehash(nkeys);
+    for (int i = 0; i < nkeys; ++i) { if (m.find(i) == m.end()) return false; }
+    for (int i = nkeys; i < nkeys * 2; ++i) {
+      if (m.find(i) != m.end()) return false;
+    }
+    return true;
+  }
+  static bool erase_iterator() {
+    map_type<int64_t, int64_t> m;
+    int nkeys = 10 * 1000;
+    for (int i = 0; i < nkeys; ++i) { m.insert(make_pair(i, i)); }
+    for (int i = nkeys; i >= 0; --i) { 
+      m.erase(m.find(i));
+      if (static_cast<int>(m.size()) != i) return false;
+    }
+    return true;
+  }
+ static bool erase_value() {
+    map_type<int64_t, int64_t> m;
+    int nkeys = 10 * 1000;
+    for (int i = 0; i < nkeys; ++i) { m.insert(make_pair(i, i)); }
+    for (int i = nkeys; i >= 0; --i) { 
+      m.erase(i);
+      if (static_cast<int>(m.size()) != i) return false;
+    }
+    return true;
+  }
 };
 
 }  // namespace cxxxmph
diff --git a/cxxmph/map_tester_test.cc b/cxxmph/map_tester_test.cc
index d83697d..9091d0b 100644
--- a/cxxmph/map_tester_test.cc
+++ b/cxxmph/map_tester_test.cc
@@ -11,3 +11,7 @@ CXXMPH_CXX_TEST_CASE(small_search, Tester::small_search);
 CXXMPH_CXX_TEST_CASE(default_search, Tester::default_search);
 CXXMPH_CXX_TEST_CASE(large_search, Tester::large_search);
 CXXMPH_CXX_TEST_CASE(string_search, Tester::string_search);
+CXXMPH_CXX_TEST_CASE(rehash_zero, Tester::rehash_zero);
+CXXMPH_CXX_TEST_CASE(rehash_size, Tester::rehash_size);
+CXXMPH_CXX_TEST_CASE(erase_value, Tester::erase_value);
+CXXMPH_CXX_TEST_CASE(erase_iterator, Tester::erase_iterator);
diff --git a/cxxmph/mph_map_test.cc b/cxxmph/mph_map_test.cc
index 3310ad4..21d1b40 100644
--- a/cxxmph/mph_map_test.cc
+++ b/cxxmph/mph_map_test.cc
@@ -17,58 +17,7 @@ CXXMPH_CXX_TEST_CASE(small_search, Tester::small_search);
 CXXMPH_CXX_TEST_CASE(default_search, Tester::default_search);
 CXXMPH_CXX_TEST_CASE(large_search, Tester::large_search);
 CXXMPH_CXX_TEST_CASE(string_search, Tester::string_search);
-
-/*
-using std::make_pair;
-using std::string;
-using cxxmph::mph_map;
-
-int main(int argc, char** argv) {
-  mph_map<int64_t, int64_t> b;
-  int32_t num_keys = 1000*10;
-  for (int i = 0; i < num_keys; ++i) {
-    b.insert(make_pair(i, i));
-  }
-  b.rehash(b.size());
-  for (int i = 0; i < 1000000; ++i) {
-    auto it = b.find(i % num_keys);
-    if (it == b.end()) {
-      std::cerr << "Failed to find " << i << std::endl;
-      exit(-1);
-    }
-    if (it->first != it->second || it->first != i % num_keys) {
-      std::cerr << "Found " << it->first << " looking for " << i << std::endl;
-      exit(-1);
-    }
-  }
-  mph_map<string, int> h;
-  h.insert(std::make_pair("-1",-1));
-  mph_map<string, int>::const_iterator it;
-  for (it = h.begin(); it != h.end(); ++it) {
-    if (it->second != -1) exit(-1);
-  }
-  int32_t num_valid = 100;
-  for (int i = 0; i < num_valid; ++i) {
-     char buf[10];    
-     snprintf(buf, 10, "%d", i);
-     h.insert(std::make_pair(buf, i));
-  }
-  for (int j = 0; j < 100; ++j) {
-    for (int i = 1000; i > 0; --i) {
-       char buf[10];    
-       snprintf(buf, 10, "%d", i - 1);
-       auto it = h.find(buf);
-       if (i < num_valid && it->second != i - 1) exit(-1);
-    }
-  }
-  for (int j = 0; j < 100; ++j) {
-    for (int i = 1000; i > 0; --i) {
-       char buf[10];    
-       int key = i*100 - 1;
-       snprintf(buf, 10, "%d", key);
-       auto it = h.find(buf);
-       if (key < num_valid && it->second != key) exit(-1);
-    }
-  }
-}
-*/
+CXXMPH_CXX_TEST_CASE(rehash_zero, Tester::rehash_zero);
+CXXMPH_CXX_TEST_CASE(rehash_size, Tester::rehash_size);
+CXXMPH_CXX_TEST_CASE(erase_value, Tester::erase_value);
+CXXMPH_CXX_TEST_CASE(erase_iterator, Tester::erase_iterator);