diff --git a/cpp/Makefile b/cpp/Makefile
index 10a50a3..9fef9a3 100644
--- a/cpp/Makefile
+++ b/cpp/Makefile
@@ -1,5 +1,5 @@
 CXXFLAGS += -O3 -Wall
-CXXFLAGS += -pg
+# CXXFLAGS += -pg
 
 # Add .d to Make's recognized suffixes.
 SUFFIXES += .d
diff --git a/cpp/src/model/ais/v1_simple.cpp b/cpp/src/model/ais/v1_simple.cpp
index 0eab1a9..15eaf6f 100644
--- a/cpp/src/model/ais/v1_simple.cpp
+++ b/cpp/src/model/ais/v1_simple.cpp
@@ -4,7 +4,7 @@
 
 #include <map>
 
-#define MULTITHREADED 0
+#define MULTITHREADED 1
 
 static int INFINITY = std::numeric_limits<int>::max();