diff --git a/deps/Makefile b/deps/Makefile
index 70970fe..6c83d0e 100644
--- a/deps/Makefile
+++ b/deps/Makefile
@@ -34,15 +34,21 @@ endif
 BASE_FLAGS += -I$(abspath ../include)
 BASE_FLAGS += -I$(abspath ../include/simd-compat)
 
+# SSE must always be enabled, even in debug builds
+ifeq ($(CPU_I386_OR_X86_64),true)
+BASE_FLAGS += -msse -msse2 -msse3
+ifeq ($(WASM),true)
+BASE_FLAGS += -msimd128
+endif
+endif
+
 ifeq ($(HAIKU)$(WASM),true)
 BASE_FLAGS += -I$(abspath ../include/linux-compat)
 endif
 
-ifeq ($(HEADLESS),true)
-ifeq ($(WITH_LTO),true)
+ifeq ($(MOD_BUILD)$(WITH_LTO),true)
 BASE_FLAGS += -ffat-lto-objects
 endif
-endif
 
 ifneq ($(SYSDEPS),true)
 BASE_FLAGS += -DZSTDLIB_VISIBILITY=
diff --git a/plugins/Makefile b/plugins/Makefile
index bbc2bd6..0ba155c 100644
--- a/plugins/Makefile
+++ b/plugins/Makefile
@@ -1202,7 +1202,7 @@ BUILD_CXX_FLAGS += -fno-finite-math-only -fno-strict-aliasing
 ifneq ($(MACOS),true)
 BUILD_CXX_FLAGS += -faligned-new -Wno-abi
 ifeq ($(MOD_BUILD),true)
-BUILD_CXX_FLAGS += -fabi-version=11
+BUILD_CXX_FLAGS += -fabi-version=12
 endif
 endif
 
diff --git a/src/Makefile b/src/Makefile
index 483e42b..aaa90ac 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -113,7 +113,7 @@ BUILD_CXX_FLAGS += -fno-finite-math-only -fno-strict-aliasing
 ifneq ($(MACOS),true)
 BUILD_CXX_FLAGS += -faligned-new -Wno-abi
 ifeq ($(MOD_BUILD),true)
-BUILD_CXX_FLAGS += -fabi-version=11
+BUILD_CXX_FLAGS += -fabi-version=12
 endif
 endif
 
diff --git a/src/Makefile.cardinal.mk b/src/Makefile.cardinal.mk
index 84e5fa0..444b01d 100644
--- a/src/Makefile.cardinal.mk
+++ b/src/Makefile.cardinal.mk
@@ -289,8 +289,8 @@ BUILD_CXX_FLAGS += -fno-finite-math-only -fno-strict-aliasing
 ifneq ($(MACOS),true)
 BUILD_CXX_FLAGS += -faligned-new -Wno-abi
 ifeq ($(MOD_BUILD),true)
-BUILD_CXX_FLAGS += -fabi-version=11
-LINK_FLAGS      += -fabi-version=11
+BUILD_CXX_FLAGS += -fabi-version=12
+LINK_FLAGS      += -fabi-version=12
 endif
 endif