diff --git a/.circleci/config.yml b/.circleci/config.yml
index aa1b684a2..db763614a 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -81,7 +81,7 @@ jobs:
       - run: make -j32
       - run: make check || .ci/fail.sh
 
-  archlinux-debug-O0-py3:
+  archlinux-py3-all:
     docker:
       - image: base/devel
     steps:
@@ -90,9 +90,9 @@ jobs:
       - run: pip install flake8 fonttools
       - run: flake8 . --count --select=E901,E999,F821,F822,F823 --show-source --statistics
       # C??FLAGS are not needed for a regular build
-      - run: CFLAGS="-O0" CXXFLAGS="-O0" CPPFLAGS="-DHB_DEBUG" ./autogen.sh --with-freetype --with-glib --with-gobject --with-cairo --with-icu --with-graphite2
-      - run: make -j32
-      - run: make check || .ci/fail.sh
+      - run: CFLAGS="-Wall -Wextra -Wno-cast-function-type" CXXFLAGS="-Wall -Wextra -Wno-unused-parameter -Wno-missing-field-initializers -Wno-class-memaccess -Wpedantic -Wno-format -Wno-cast-function-type" ./autogen.sh --with-freetype --with-glib --with-gobject --with-cairo --with-icu --with-graphite2
+      - run: make -j32 CPPFLAGS="-Werror"
+      - run: make check CPPFLAGS="-Werror" || .ci/fail.sh
 
   clang-O3-O0:
     docker:
@@ -208,13 +208,13 @@ jobs:
       - run: make -j32
       - run: make check || .ci/fail.sh | asan_symbolize | c++filt
 
-  fedora-outoftreebuild:
+  fedora-O0-debug-outoftreebuild:
     docker:
       - image: fedora
     steps:
       - checkout
       - run: dnf install -y pkg-config ragel gcc gcc-c++ automake autoconf libtool make which glib2-devel freetype-devel cairo-devel libicu-devel gobject-introspection-devel graphite2-devel redhat-rpm-config python || true
-      - run: NOCONFIGURE=1 ./autogen.sh --with-freetype --with-glib --with-gobject --with-cairo --with-icu --with-graphite2
+      - run: CFLAGS="-O0" CXXFLAGS="-O0" CPPFLAGS="-DHB_DEBUG" NOCONFIGURE=1 ./autogen.sh --with-freetype --with-glib --with-gobject --with-cairo --with-icu --with-graphite2
       - run: mkdir build && cd build && ../configure && make && (make check || ../.ci/fail.sh)
 
   cmake-gcc:
@@ -331,7 +331,7 @@ workflows:
 
       # autotools based builds
       - alpine-O3-NOMMAP
-      - archlinux-debug-O0-py3
+      - archlinux-py3-all
       - gcc-valgrind
       - clang-O3-O0
       - clang-everything
@@ -339,7 +339,7 @@ workflows:
       - clang-msan
       - clang-tsan
       - clang-ubsan
-      - fedora-outoftreebuild
+      - fedora-O0-debug-outoftreebuild
 
       # cmake based builds
       - cmake-gcc
diff --git a/src/hb-gobject-structs.cc b/src/hb-gobject-structs.cc
index 846240e93..3cff880aa 100644
--- a/src/hb-gobject-structs.cc
+++ b/src/hb-gobject-structs.cc
@@ -64,7 +64,7 @@ hb_gobject_##name##_get_type () \
 }
 
 #define HB_DEFINE_OBJECT_TYPE(name) \
-	HB_DEFINE_BOXED_TYPE (name, hb_##name##_reference, hb_##name##_destroy);
+	HB_DEFINE_BOXED_TYPE (name, hb_##name##_reference, hb_##name##_destroy)
 
 #define HB_DEFINE_VALUE_TYPE(name) \
 	static hb_##name##_t *_hb_##name##_reference (const hb_##name##_t *l) \
@@ -75,7 +75,7 @@ hb_gobject_##name##_get_type () \
 	  return c; \
 	} \
 	static void _hb_##name##_destroy (hb_##name##_t *l) { free (l); } \
-	HB_DEFINE_BOXED_TYPE (name, _hb_##name##_reference, _hb_##name##_destroy);
+	HB_DEFINE_BOXED_TYPE (name, _hb_##name##_reference, _hb_##name##_destroy)
 
 HB_DEFINE_OBJECT_TYPE (buffer)
 HB_DEFINE_OBJECT_TYPE (blob)