diff --git a/gtsam/base/Makefile.am b/gtsam/base/Makefile.am
index 4d10680f3..c01b20f7a 100644
--- a/gtsam/base/Makefile.am
+++ b/gtsam/base/Makefile.am
@@ -25,6 +25,7 @@ endif
 # Testing
 headers += Testable.h TestableAssertions.h numericalDerivative.h
 sources += timing.cpp debug.cpp
+check_PROGRAMS += tests/testDebug
 
 # Lie Groups
 headers += Lie.h Lie-inl.h lieProxies.h LieScalar.h
diff --git a/gtsam/base/debug.cpp b/gtsam/base/debug.cpp
index 57951d756..4da6dc6c6 100644
--- a/gtsam/base/debug.cpp
+++ b/gtsam/base/debug.cpp
@@ -9,8 +9,6 @@
 
 namespace gtsam {
 
-#ifdef GTSAM_ENABLE_DEBUG
   FastMap<std::string, ValueWithDefault<bool,false> > debugFlags;
-#endif
 
 }
diff --git a/gtsam/base/debug.h b/gtsam/base/debug.h
index 215766661..51074bd46 100644
--- a/gtsam/base/debug.h
+++ b/gtsam/base/debug.h
@@ -5,8 +5,6 @@
  * @created Feb 1, 2011
  */
 
-#pragma once
-
 #include <gtsam/base/FastMap.h>
 #include <gtsam/base/types.h>
 #include <string>
@@ -32,19 +30,22 @@
 #endif
 #endif
 
-#ifdef GTSAM_ENABLE_DEBUG
-
 namespace gtsam {
   extern FastMap<std::string, ValueWithDefault<bool,false> > debugFlags;
 }
 
+#undef ISDEBUG
+#undef SETDEBUG
+
+#ifdef GTSAM_ENABLE_DEBUG
+
 #define ISDEBUG(S) (gtsam::debugFlags[S])
-#define SETDEBUG(S,V) (gtsam::debugFlags[S] = (V))
+#define SETDEBUG(S,V) ((void)(gtsam::debugFlags[S] = (V)))
 
 #else
 
 #define ISDEBUG(S) (false)
-#define SETDEBUG(S,V) (false)
+#define SETDEBUG(S,V) ((void)false)
 
 #endif
 
diff --git a/gtsam/base/tests/testDebug.cpp b/gtsam/base/tests/testDebug.cpp
new file mode 100644
index 000000000..49e86a307
--- /dev/null
+++ b/gtsam/base/tests/testDebug.cpp
@@ -0,0 +1,53 @@
+/* ----------------------------------------------------------------------------
+
+ * GTSAM Copyright 2010, Georgia Tech Research Corporation,
+ * Atlanta, Georgia 30332-0415
+ * All Rights Reserved
+ * Authors: Frank Dellaert, et al. (see THANKS for the full author list)
+
+ * See LICENSE for the license information
+
+ * -------------------------------------------------------------------------- */
+
+/**
+ * @file    testCholesky.cpp
+ * @brief   
+ * @author  Richard Roberts
+ * @created Feb 14, 2011
+ */
+
+#include <CppUnitLite/TestHarness.h>
+
+#define NDEBUG
+#undef GTSAM_ENABLE_DEBUG
+#include <gtsam/base/debug.h>
+
+/* ************************************************************************* */
+TEST(Debug, debug_disabled) {
+  const bool debug1 = ISDEBUG("TestDebug");
+  EXPECT(!debug1);
+
+  SETDEBUG("TestDebug", true);
+  bool debug2 = ISDEBUG("TestDebug");
+  EXPECT(!debug2);
+}
+
+#define GTSAM_ENABLE_DEBUG
+#include <gtsam/base/debug.h>
+
+/* ************************************************************************* */
+TEST(Debug, debug_enabled) {
+  const bool debug1 = ISDEBUG("TestDebug");
+  EXPECT(!debug1);
+
+  SETDEBUG("TestDebug", true);
+  bool debug2 = ISDEBUG("TestDebug");
+  EXPECT(debug2);
+}
+
+/* ************************************************************************* */
+int main() {
+  TestResult tr;
+  return TestRegistry::runAllTests(tr);
+}
+/* ************************************************************************* */