diff --git a/configure.ac b/configure.ac
index e481e80..4e89854 100644
--- a/configure.ac
+++ b/configure.ac
@@ -163,20 +163,30 @@
 AS_IF([test "x$enable_cooling_type" != "xno"], [
        AC_CONFIG_FILES([cooling-type/Makefile])
 ])
+
 AS_IF([test "x$enable_monitor" != "xno"], [
+    # Use runtime(json) config, otherwise default to compile time(yaml) config
+    AM_COND_IF([WANT_JSON],
+    [
+        AC_CHECK_HEADER(nlohmann/json.hpp, ,
+                [AC_MSG_ERROR([Could not find nlohmann/json.hpp... nlohmann/json package required])])
+        # Set config flag for runtime json usage
+        AC_DEFINE([MONITOR_USE_JSON], [1], [Fan monitor use runtime json configuration])
+        AC_MSG_NOTICE([Fan monitor json configuration usage enabled])
+    ],
+    [
+        AC_ARG_VAR(FAN_MONITOR_YAML_FILE,
+                   [The fan monitor definition file to use])
+        AS_IF([test "x$FAN_MONITOR_YAML_FILE" == "x"],
+              [FAN_MONITOR_YAML_FILE="\${top_srcdir}/monitor/example/monitor.yaml"])
+        AC_DEFINE_UNQUOTED([FAN_MONITOR_YAML_FILE], ["$FAN_MONITOR_YAML_FILE"],
+                           [The fan monitor definition file to use])
 
-       AC_ARG_VAR(FAN_MONITOR_YAML_FILE,
-                  [The fan monitor definition file to use])
-       AS_IF([test "x$FAN_MONITOR_YAML_FILE" == "x"],
-             [FAN_MONITOR_YAML_FILE="\${top_srcdir}/monitor/example/monitor.yaml"])
-       AC_DEFINE_UNQUOTED([FAN_MONITOR_YAML_FILE], ["$FAN_MONITOR_YAML_FILE"],
-                          [The fan monitor definition file to use])
-
-       AC_SUBST([GEN_FAN_MONITOR_DEFS],
-                ["$PYTHON \${top_srcdir}/monitor/gen-fan-monitor-defs.py \
-                         -m $FAN_MONITOR_YAML_FILE"])
-
-       AC_CONFIG_FILES([monitor/Makefile])
+        AC_SUBST([GEN_FAN_MONITOR_DEFS],
+                 ["$PYTHON \${top_srcdir}/monitor/gen-fan-monitor-defs.py \
+                  -m $FAN_MONITOR_YAML_FILE"])
+    ])
+    AC_CONFIG_FILES([monitor/Makefile])
 ])
 
 # Create configured output
diff --git a/monitor/Makefile.am b/monitor/Makefile.am
index 9575244..185c2e3 100644
--- a/monitor/Makefile.am
+++ b/monitor/Makefile.am
@@ -11,11 +11,6 @@
 	tach_sensor.cpp \
 	conditions.cpp
 
-nodist_phosphor_fan_monitor_SOURCES = \
-	fan_monitor_defs.cpp
-
-BUILT_SOURCES = fan_monitor_defs.cpp
-
 phosphor_fan_monitor_LDADD = \
 	$(SDBUSPLUS_LIBS) \
 	$(SDEVENTPLUS_LIBS) \
@@ -30,5 +25,13 @@
 	${PHOSPHOR_DBUS_INTERFACES_CFLAGS} \
 	-flto
 
+if WANT_JSON
+phosphor_fan_monitor_SOURCES += json_parser.cpp
+else
+BUILT_SOURCES = fan_monitor_defs.cpp
+nodist_phosphor_fan_monitor_SOURCES = \
+	fan_monitor_defs.cpp
+
 fan_monitor_defs.cpp: ${srcdir}/gen-fan-monitor-defs.py
 	$(AM_V_GEN)$(GEN_FAN_MONITOR_DEFS) > ${builddir}/$@
+endif