diff --git a/tests/libfixmath_unittests/Makefile b/tests/libfixmath_unittests/Makefile
index d7670a148d..cda7ef5588 100644
--- a/tests/libfixmath_unittests/Makefile
+++ b/tests/libfixmath_unittests/Makefile
@@ -2,7 +2,8 @@ include ../Makefile.tests_common
 
 BOARD_BLACKLIST := arduino-duemilanove arduino-leonardo \
                    arduino-mega2560 arduino-nano arduino-uno \
-                   atmega328p mega-xplained microduino-corerf waspmote-pro
+                   atmega328p atmega256rfr2-xpro mega-xplained \
+                   microduino-corerf waspmote-pro
 # arduino-mega2560: builds locally but breaks travis (possibly because of
 # differences in the toolchain)
 # The MSP boards don't feature round(), exp(), and log(), which are used in the unittests
diff --git a/tests/pkg_libb2/Makefile.ci b/tests/pkg_libb2/Makefile.ci
index 8746e758e2..898f99323e 100644
--- a/tests/pkg_libb2/Makefile.ci
+++ b/tests/pkg_libb2/Makefile.ci
@@ -3,6 +3,7 @@ BOARD_INSUFFICIENT_MEMORY := \
     arduino-leonardo \
     arduino-nano \
     arduino-uno \
+    atmega256rfr2-xpro \
     atmega328p \
     chronos \
     mega-xplained \
diff --git a/tests/pkg_relic/Makefile b/tests/pkg_relic/Makefile
index 726e3e0a92..0d13d8887e 100644
--- a/tests/pkg_relic/Makefile
+++ b/tests/pkg_relic/Makefile
@@ -6,6 +6,7 @@ BOARD_BLACKLIST :=  arduino-duemilanove \
                     arduino-mega2560 \
                     arduino-nano \
                     arduino-uno \
+                    atmega256rfr2-xpro \
                     atmega328p \
                     chronos \
                     f4vi1 \
diff --git a/tests/pkg_tweetnacl/Makefile.ci b/tests/pkg_tweetnacl/Makefile.ci
index 90279652a7..ee2dd63316 100644
--- a/tests/pkg_tweetnacl/Makefile.ci
+++ b/tests/pkg_tweetnacl/Makefile.ci
@@ -4,6 +4,7 @@ BOARD_INSUFFICIENT_MEMORY := \
     arduino-mega2560 \
     arduino-nano \
     arduino-uno \
+    atmega256rfr2-xpro \
     atmega328p \
     mega-xplained \
     microduino-corerf \
diff --git a/tests/pthread_cooperation/Makefile.ci b/tests/pthread_cooperation/Makefile.ci
index e032327134..0ec3ff3842 100644
--- a/tests/pthread_cooperation/Makefile.ci
+++ b/tests/pthread_cooperation/Makefile.ci
@@ -4,6 +4,7 @@ BOARD_INSUFFICIENT_MEMORY := \
     arduino-mega2560 \
     arduino-nano \
     arduino-uno \
+    atmega256rfr2-xpro \
     atmega328p \
     hifive1 \
     hifive1b \
diff --git a/tests/sys_crypto/Makefile b/tests/sys_crypto/Makefile
index f679a834db..75616a82cc 100644
--- a/tests/sys_crypto/Makefile
+++ b/tests/sys_crypto/Makefile
@@ -6,6 +6,7 @@ BOARD_BLACKLIST += arduino-leonardo
 BOARD_BLACKLIST += arduino-mega2560
 BOARD_BLACKLIST += arduino-nano
 BOARD_BLACKLIST += arduino-uno
+BOARD_BLACKLIST += atmega256rfr2-xpro
 BOARD_BLACKLIST += atmega328p
 BOARD_BLACKLIST += chronos
 BOARD_BLACKLIST += mega-xplained
diff --git a/tests/unittests/Makefile.ci b/tests/unittests/Makefile.ci
index 20d478fe33..d2e0dc0391 100644
--- a/tests/unittests/Makefile.ci
+++ b/tests/unittests/Makefile.ci
@@ -9,6 +9,7 @@ BOARD_INSUFFICIENT_MEMORY := \
     arduino-mkrzero \
     arduino-nano \
     arduino-uno \
+    atmega256rfr2-xpro \
     atmega328p \
     arduino-zero \
     b-l072z-lrwan1 \