diff --git a/src/libdoxygen.pro.in b/src/libdoxygen.pro.in
index b230b2f..a9a3639 100644
--- a/src/libdoxygen.pro.in
+++ b/src/libdoxygen.pro.in
@@ -244,7 +244,7 @@ SOURCES      =	arguments.cpp \
 win32:TMAKE_CXXFLAGS       += -DQT_NODLL 
 win32-msvc:TMAKE_CXXFLAGS  += -Zm200
 win32-g++:TMAKE_CXXFLAGS   += -fno-exceptions
-linux-g++:TMAKE_CXXFLAGS    += -fno-exceptions
+linux-g++:TMAKE_CXXFLAGS    += -fno-exceptions -fsigned-char
 INCLUDEPATH                += ../qtools
 #INCLUDEPATH                += ../libpng
 INCLUDEPATH                += ../libmd5
