diff --git a/tools/cooja/config/external_tools_linux.config b/tools/cooja/config/external_tools_linux.config
index a670b0852..85825894f 100644
--- a/tools/cooja/config/external_tools_linux.config
+++ b/tools/cooja/config/external_tools_linux.config
@@ -13,7 +13,7 @@ CMD_GREP_INTERFACES = grep "^SIM_INTERFACE([^,]*," -o -d skip -D skip -H -r
 REGEXP_PARSE_INTERFACES = ([^/]*.c):SIM_INTERFACE\\(([^,]*),
 CMD_GREP_SENSORS = grep "^SENSORS_SENSOR([^,]*," -o -d skip -D skip -H -r
 REGEXP_PARSE_SENSORS = ([^/]*.c):SENSORS_SENSOR\\(([^,]*),
-COMPILER_ARGS = -I'$(JAVA_HOME)/include' -I'$(JAVA_HOME)/include/linux'
+COMPILER_ARGS = -I'$(JAVA_HOME)/include' -I'$(JAVA_HOME)/include/linux' -fno-builtin-printf
 LINK_COMMAND_1 = gcc -I'$(JAVA_HOME)/include' -I'$(JAVA_HOME)/include/linux' -shared -Wl,-Map=$(MAPFILE) -o $(LIBFILE)
 LINK_COMMAND_2 =
 AR_COMMAND_1 = ar rcf $(ARFILE)
diff --git a/tools/cooja/config/external_tools_win32.config b/tools/cooja/config/external_tools_win32.config
index f31ed8ae6..97c17f745 100644
--- a/tools/cooja/config/external_tools_win32.config
+++ b/tools/cooja/config/external_tools_win32.config
@@ -13,7 +13,7 @@ CMD_GREP_INTERFACES = grep '^SIM_INTERFACE([^,]*,' -o -d skip -D skip -H -r
 REGEXP_PARSE_INTERFACES = ([^/]*.c):SIM_INTERFACE\\(([^,]*),
 CMD_GREP_SENSORS = grep '^SENSORS_SENSOR([^,]*,' -o -d skip -D skip -H -r
 REGEXP_PARSE_SENSORS = ([^/]*.c):SENSORS_SENSOR\\(([^,]*),
-COMPILER_ARGS = -mno-cygwin -Wall -I'$(JAVA_HOME)/include' -I'$(JAVA_HOME)/include/win32'
+COMPILER_ARGS = -mno-cygwin -Wall -I'$(JAVA_HOME)/include' -I'$(JAVA_HOME)/include/win32' -fno-builtin-printf
 LINK_COMMAND_1 = gcc -mno-cygwin -shared -Wl,-Map=$(MAPFILE) -Wl,--add-stdcall-alias -o $(LIBFILE)
 LINK_COMMAND_2 = -L/usr/lib/mingw -lmsvcrt
 AR_COMMAND_1 = ar rcf $(ARFILE)