diff --git a/scripts/get_libngspice_so.sh b/scripts/get_libngspice_so.sh
index b1d9ebb..62969a7 100755
--- a/scripts/get_libngspice_so.sh
+++ b/scripts/get_libngspice_so.sh
@@ -75,7 +75,8 @@ echo "(c) CERN 2016"
 echo "author: Maciej Suminski <maciej.suminski@cern.ch>"
 echo "contributors: madworm"
 echo
-echo "PREREQUISITES: autoconf automake bison flex gcc git libtool make"
+echo "PREREQUISITES: autoconf automake bison=2.7 flex gcc git libtool make"
+echo "for bison 2.7 and debian based os see: https://askubuntu.com/questions/444982/install-bison-2-7-in-ubuntu-14-04#answer-461961"
 echo
 
 echo "*** Downloading ngspice source code.. ***"
@@ -95,6 +96,32 @@ fi
 
 echo "*** Building libngspice shared library.. ***"
 git checkout ${SNAPSHOT_REV}
+
+# patch for flex -o problem, see https://github.com/ellson/MOTHBALLED-graphviz/issues/1184#issuecomment-267042766
+echo "applying patch for flex -o problem"
+git apply <<'EOF'
+diff --git a/src/xspice/cmpp/Makefile.am b/src/xspice/cmpp/Makefile.am
+index e38bfe1..4b1e35b 100644
+--- a/src/xspice/cmpp/Makefile.am
++++ b/src/xspice/cmpp/Makefile.am
+@@ -17,13 +17,13 @@ cmpp_SOURCES = main.c cmpp.h \
+ 	mod_lex.l mod_yacc.y mod_yacc_y.h
+ 
+ mod_lex.c : mod_lex.l
+-	$(am__skiplex) $(LEXCOMPILE) -o $@ $<
++	$(am__skiplex) $(LEXCOMPILE) -o$@ $<
+ 
+ mod_yacc.c : mod_yacc.y
+ 	$(am__skipyacc) $(YACCCOMPILE) -o $@ $<
+ 
+ ifs_lex.c : ifs_lex.l
+-	$(am__skiplex) $(LEXCOMPILE) -o $@ $<
++	$(am__skiplex) $(LEXCOMPILE) -o$@ $<
+ 
+ ifs_yacc.c : ifs_yacc.y
+ 	$(am__skipyacc) $(YACCCOMPILE) -o $@ $<
+EOF
+
 ./autogen.sh
 ./configure --with-ngshared --enable-xspice --enable-cider ${CFG_OPTIONS}
 make