diff --git a/Makefile b/Makefile
index cc9ee60c..3b5ebec6 100644
--- a/Makefile
+++ b/Makefile
@@ -111,7 +111,7 @@ objs/stdlib-c.o: objs/stdlib-c.cpp
 
 objs/stdlib_ispc.cpp: stdlib.ispc
 	@echo Creating C++ source from $<
-	@$(CPP) -DISPC=1 -DPI=3.1415936535 $< | ./stdlib2cpp.py > $@
+	@$(CPP) -DISPC=1 -DPI=3.1415926536 $< | ./stdlib2cpp.py > $@
 
 objs/stdlib_ispc.o: objs/stdlib_ispc.cpp
 	@echo Compiling $<