diff --git a/glibc_2.23/mmap_overlapping_chunks.c b/glibc_2.23/mmap_overlapping_chunks.c
index 4834958..6a2808b 100644
--- a/glibc_2.23/mmap_overlapping_chunks.c
+++ b/glibc_2.23/mmap_overlapping_chunks.c
@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <assert.h>
+#include <unistd.h>
 
 /*
 Technique should work on all versions of GLibC
diff --git a/glibc_2.24/mmap_overlapping_chunks.c b/glibc_2.24/mmap_overlapping_chunks.c
index 4834958..6a2808b 100644
--- a/glibc_2.24/mmap_overlapping_chunks.c
+++ b/glibc_2.24/mmap_overlapping_chunks.c
@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <assert.h>
+#include <unistd.h>
 
 /*
 Technique should work on all versions of GLibC
diff --git a/glibc_2.27/mmap_overlapping_chunks.c b/glibc_2.27/mmap_overlapping_chunks.c
index 4834958..6a2808b 100644
--- a/glibc_2.27/mmap_overlapping_chunks.c
+++ b/glibc_2.27/mmap_overlapping_chunks.c
@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <assert.h>
+#include <unistd.h>
 
 /*
 Technique should work on all versions of GLibC
diff --git a/glibc_2.31/mmap_overlapping_chunks.c b/glibc_2.31/mmap_overlapping_chunks.c
index 4834958..6a2808b 100644
--- a/glibc_2.31/mmap_overlapping_chunks.c
+++ b/glibc_2.31/mmap_overlapping_chunks.c
@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <assert.h>
+#include <unistd.h>
 
 /*
 Technique should work on all versions of GLibC
diff --git a/glibc_2.32/mmap_overlapping_chunks.c b/glibc_2.32/mmap_overlapping_chunks.c
index 4834958..6a2808b 100644
--- a/glibc_2.32/mmap_overlapping_chunks.c
+++ b/glibc_2.32/mmap_overlapping_chunks.c
@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <assert.h>
+#include <unistd.h>
 
 /*
 Technique should work on all versions of GLibC
diff --git a/glibc_2.33/mmap_overlapping_chunks.c b/glibc_2.33/mmap_overlapping_chunks.c
index 4834958..6a2808b 100644
--- a/glibc_2.33/mmap_overlapping_chunks.c
+++ b/glibc_2.33/mmap_overlapping_chunks.c
@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <assert.h>
+#include <unistd.h>
 
 /*
 Technique should work on all versions of GLibC
diff --git a/glibc_2.34/mmap_overlapping_chunks.c b/glibc_2.34/mmap_overlapping_chunks.c
index 4834958..6a2808b 100644
--- a/glibc_2.34/mmap_overlapping_chunks.c
+++ b/glibc_2.34/mmap_overlapping_chunks.c
@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <assert.h>
+#include <unistd.h>
 
 /*
 Technique should work on all versions of GLibC
diff --git a/glibc_2.35/mmap_overlapping_chunks.c b/glibc_2.35/mmap_overlapping_chunks.c
index 4834958..6a2808b 100644
--- a/glibc_2.35/mmap_overlapping_chunks.c
+++ b/glibc_2.35/mmap_overlapping_chunks.c
@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <assert.h>
+#include <unistd.h>
 
 /*
 Technique should work on all versions of GLibC
diff --git a/glibc_2.36/mmap_overlapping_chunks.c b/glibc_2.36/mmap_overlapping_chunks.c
index 4834958..6a2808b 100644
--- a/glibc_2.36/mmap_overlapping_chunks.c
+++ b/glibc_2.36/mmap_overlapping_chunks.c
@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <assert.h>
+#include <unistd.h>
 
 /*
 Technique should work on all versions of GLibC
diff --git a/glibc_2.37/mmap_overlapping_chunks.c b/glibc_2.37/mmap_overlapping_chunks.c
index 4834958..6a2808b 100644
--- a/glibc_2.37/mmap_overlapping_chunks.c
+++ b/glibc_2.37/mmap_overlapping_chunks.c
@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <assert.h>
+#include <unistd.h>
 
 /*
 Technique should work on all versions of GLibC
diff --git a/glibc_2.38/mmap_overlapping_chunks.c b/glibc_2.38/mmap_overlapping_chunks.c
index 4834958..6a2808b 100644
--- a/glibc_2.38/mmap_overlapping_chunks.c
+++ b/glibc_2.38/mmap_overlapping_chunks.c
@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <assert.h>
+#include <unistd.h>
 
 /*
 Technique should work on all versions of GLibC
diff --git a/glibc_2.39/mmap_overlapping_chunks.c b/glibc_2.39/mmap_overlapping_chunks.c
index 4834958..6a2808b 100644
--- a/glibc_2.39/mmap_overlapping_chunks.c
+++ b/glibc_2.39/mmap_overlapping_chunks.c
@@ -1,6 +1,7 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <assert.h>
+#include <unistd.h>
 
 /*
 Technique should work on all versions of GLibC