diff --git a/repos/ports/ports/seoul.hash b/repos/ports/ports/seoul.hash
index d6a3fd120a..f3347f16eb 100644
--- a/repos/ports/ports/seoul.hash
+++ b/repos/ports/ports/seoul.hash
@@ -1 +1 @@
-e4c5e41a5d3b5398a310dbc39b52a5393526c816
+d5d5885b5e485bc58d541b1f76a7518f169acc20
diff --git a/repos/ports/ports/seoul.port b/repos/ports/ports/seoul.port
index 945118f92c..d0f1509557 100644
--- a/repos/ports/ports/seoul.port
+++ b/repos/ports/ports/seoul.port
@@ -3,8 +3,8 @@ VERSION   := git
 DOWNLOADS := seoul.git
 
 URL(seoul) := https://github.com/alex-ab/seoul.git
-# branch genode_20_11
-REV(seoul) := 9c009e7ad2b5ec9fbafdc731e8796f33ff90e921
+# branch genode_21_05
+REV(seoul) := dc21f28de3c9d1a4f99df6da346663ce191f1978
 DIR(seoul) := src/app/seoul
 
 #
diff --git a/repos/ports/src/app/seoul/target.mk b/repos/ports/src/app/seoul/target.mk
index c2891fdd98..06a97293f8 100644
--- a/repos/ports/src/app/seoul/target.mk
+++ b/repos/ports/src/app/seoul/target.mk
@@ -24,11 +24,7 @@ INC_DIR += $(SEOUL_GENODE_DIR)/include
 INC_DIR += $(REP_DIR)/src/app/seoul/include
 include $(call select_from_repositories,lib/mk/libc-common.inc)
 
-CC_CXX_WARN_STRICT = -Wextra -Weffc++ -Werror
-CC_WARN += -Wno-parentheses -Wall -Wno-unused
-
-# XXX fix the warnings and remove this option
-CC_WARN += -Wno-error=implicit-fallthrough
+CC_WARN += -Wno-unused
 
 CC_CXX_OPT += -march=core2
 CC_OPT_model/intel82576vf := -mssse3