diff --git a/Makefile.configure b/Makefile.configure
index 16bab6bb..6ccc402c 100644
--- a/Makefile.configure
+++ b/Makefile.configure
@@ -15,8 +15,9 @@ PROGRAM-freestanding += int main() {}
 CCFLAGS-freestanding = $(CFLAGS)
 
 PROGRAM-cjson  = \#include <stdlib.h>\n
+PROGRAM-cjson += \#include <float.h>\n
 PROGRAM-cjson += \#include <cjson/cJSON.h>\n
-PROGRAM-cjson += int main() { return cJSON_False; }
+PROGRAM-cjson += int main() { double d = NAN; return cJSON_False; }
 CCFLAGS-cjson = -I$(dir $(MAKEFILE))src
 PROGRAM-system-cjson = $(PROGRAM-cjson)
 CCFLAGS-system-cjson = -lcjson