1diff --git a/OfficeUtils/OfficeUtils.pri b/OfficeUtils/OfficeUtils.pri
2index b4e1f497a8..6d99014ddd 100644
3--- a/OfficeUtils/OfficeUtils.pri
4+++ b/OfficeUtils/OfficeUtils.pri
5@@ -1,5 +1,6 @@
6 core_linux {
7 QMAKE_CXXFLAGS += -Wall -Wno-ignored-qualifiers
8+ QMAKE_CFLAGS += -DSTDC
9 }
10 core_mac {
11 QMAKE_CXXFLAGS += -Wall -Wno-ignored-qualifiers
12diff --git a/OfficeUtils/src/zlib-1.2.11/gzguts.h b/OfficeUtils/src/zlib-1.2.11/gzguts.h
13index 990a4d2514..aefbbd8879 100644
14--- a/OfficeUtils/src/zlib-1.2.11/gzguts.h
15+++ b/OfficeUtils/src/zlib-1.2.11/gzguts.h
16@@ -24,6 +24,7 @@
17 # include <string.h>
18 # include <stdlib.h>
19 # include <limits.h>
20+# include <unistd.h>
21 #endif
22
23 #ifndef _POSIX_SOURCE