diff --git a/stim/ui/progressbar.h b/stim/ui/progressbar.h
index 445d6a4..b11e377 100644
--- a/stim/ui/progressbar.h
+++ b/stim/ui/progressbar.h
@@ -3,6 +3,7 @@
 
 #include <iostream>
 #include <sstream>
+#include <iomanip>
 using namespace std;
 
 void stimPrintTime(unsigned long long s) {
--
libgit2 0.21.4