diff --git a/pkg/qcbor/Makefile b/pkg/qcbor/Makefile
index a995413d6a..41f7bf5817 100644
--- a/pkg/qcbor/Makefile
+++ b/pkg/qcbor/Makefile
@@ -5,5 +5,11 @@ PKG_LICENSE = BSD-3-Clause
 
 include $(RIOTBASE)/pkg/pkg.mk
 
+# some variable seem uninitialized to gcc with -Og but are not
+# https://gcc.gnu.org/bugzilla/buglist.cgi?quicksearch=may%20be%20used%20uninitialized
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42145
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90710#c1
+CFLAGS += -Wno-maybe-uninitialized
+
 all:
 	"$(MAKE)" -C $(PKG_SOURCE_DIR)/src -f $(RIOTBASE)/Makefile.base MODULE=$(PKG_NAME)
diff --git a/pkg/wakaama/Makefile b/pkg/wakaama/Makefile
index 0238324760..5cea8c9bae 100644
--- a/pkg/wakaama/Makefile
+++ b/pkg/wakaama/Makefile
@@ -5,6 +5,12 @@ PKG_LICENSE=EDL-1.0,EPL-1.0
 
 include $(RIOTBASE)/pkg/pkg.mk
 
+# some variable seem uninitialized to gcc with -Og but are not
+# https://gcc.gnu.org/bugzilla/buglist.cgi?quicksearch=may%20be%20used%20uninitialized
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42145
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90710#c1
+CFLAGS += -Wno-maybe-uninitialized
+
 all:
 	"$(MAKE)" -C $(PKG_SOURCE_DIR)/core -f $(RIOTBASE)/Makefile.base MODULE=wakaama_core
 	"$(MAKE)" -C $(PKG_SOURCE_DIR)/core/er-coap-13 -f $(RIOTBASE)/Makefile.base MODULE=wakaama_core_coap13
diff --git a/pkg/wolfssl/Makefile b/pkg/wolfssl/Makefile
index 109e9de4b4..4e57baab62 100644
--- a/pkg/wolfssl/Makefile
+++ b/pkg/wolfssl/Makefile
@@ -5,6 +5,12 @@ PKG_LICENSE=GPLv2
 
 include $(RIOTBASE)/pkg/pkg.mk
 
+# some variable seem uninitialized to gcc with -Og but are not
+# https://gcc.gnu.org/bugzilla/buglist.cgi?quicksearch=may%20be%20used%20uninitialized
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=42145
+# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90710#c1
+CFLAGS += -Wno-maybe-uninitialized
+
 .PHONY: wolfcrypt%
 
 all: $(filter wolfcrypt wolfcrypt-test wolfcrypt-benchmark,$(USEMODULE))