diff --git a/Problem Sets/Problem Set 1/utils.h b/Problem Sets/Problem Set 1/utils.h
index 35f954cb..7485a3da 100755
--- a/Problem Sets/Problem Set 1/utils.h	
+++ b/Problem Sets/Problem Set 1/utils.h	
@@ -8,6 +8,7 @@
 #include <cuda_runtime_api.h>
 #include <cassert>
 #include <cmath>
+#include <algorithm>
 
 #define checkCudaErrors(val) check( (val), #val, __FILE__, __LINE__)
 
diff --git a/Problem Sets/Problem Set 3/utils.h b/Problem Sets/Problem Set 3/utils.h
index 35f954cb..7485a3da 100755
--- a/Problem Sets/Problem Set 3/utils.h	
+++ b/Problem Sets/Problem Set 3/utils.h	
@@ -8,6 +8,7 @@
 #include <cuda_runtime_api.h>
 #include <cassert>
 #include <cmath>
+#include <algorithm>
 
 #define checkCudaErrors(val) check( (val), #val, __FILE__, __LINE__)
 
diff --git a/Problem Sets/Problem Set 4/utils.h b/Problem Sets/Problem Set 4/utils.h
index 35f954cb..7485a3da 100755
--- a/Problem Sets/Problem Set 4/utils.h	
+++ b/Problem Sets/Problem Set 4/utils.h	
@@ -8,6 +8,7 @@
 #include <cuda_runtime_api.h>
 #include <cassert>
 #include <cmath>
+#include <algorithm>
 
 #define checkCudaErrors(val) check( (val), #val, __FILE__, __LINE__)
 
diff --git a/Problem Sets/Problem Set 5/main.cu b/Problem Sets/Problem Set 5/main.cu
index 15071cd4..c5dcd15a 100755
--- a/Problem Sets/Problem Set 5/main.cu	
+++ b/Problem Sets/Problem Set 5/main.cu	
@@ -5,6 +5,7 @@
 #include "utils.h"
 #include "timer.h"
 #include <cstdio>
+#include <algorithm>
 #if defined(_WIN16) || defined(_WIN32) || defined(_WIN64)
 #include <Windows.h>
 #else
diff --git a/Problem Sets/Problem Set 5/utils.h b/Problem Sets/Problem Set 5/utils.h
index 35f954cb..7485a3da 100755
--- a/Problem Sets/Problem Set 5/utils.h	
+++ b/Problem Sets/Problem Set 5/utils.h	
@@ -8,6 +8,7 @@
 #include <cuda_runtime_api.h>
 #include <cassert>
 #include <cmath>
+#include <algorithm>
 
 #define checkCudaErrors(val) check( (val), #val, __FILE__, __LINE__)
 
diff --git a/Problem Sets/Problem Set 6/utils.h b/Problem Sets/Problem Set 6/utils.h
index 35f954cb..7485a3da 100755
--- a/Problem Sets/Problem Set 6/utils.h	
+++ b/Problem Sets/Problem Set 6/utils.h	
@@ -8,6 +8,7 @@
 #include <cuda_runtime_api.h>
 #include <cassert>
 #include <cmath>
+#include <algorithm>
 
 #define checkCudaErrors(val) check( (val), #val, __FILE__, __LINE__)