diff --git a/package/vo-aacenc/vo-aacenc.mk b/package/vo-aacenc/vo-aacenc.mk
index 8f01c34b7c..503876fc27 100644
--- a/package/vo-aacenc/vo-aacenc.mk
+++ b/package/vo-aacenc/vo-aacenc.mk
@@ -10,13 +10,19 @@ VO_AACENC_LICENSE = Apache-2.0
 VO_AACENC_LICENSE_FILES = COPYING
 VO_AACENC_INSTALL_STAGING = YES
 
+VO_AACENC_CFLAGS = $(TARGET_CFLAGS)
+
 # arm specific asm optimizations
 ifeq ($(BR2_arm),y)
 
+# vo-aacenc has ARM assembly code that cannot be compiled in Thumb2
+# mode, so we must force the traditional ARM mode.
+VO_AACENC_CFLAGS += -marm
+
 ifeq ($(BR2_ARM_CPU_HAS_NEON),y)
 VO_AACENC_CONF_OPT += --enable-armv7neon
 # mfpu=neon needed to assemble neon code
-VO_AACENC_CONF_ENV += CFLAGS="$(TARGET_CFLAGS) -mfpu=neon"
+VO_AACENC_CFLAGS += -mfpu=neon
 else
 VO_AACENC_CONF_OPT += --disable-armv7neon
 
@@ -29,4 +35,7 @@ endif
 endif # !neon
 endif # arm
 
+VO_AACENC_CONF_ENV = \
+	CFLAGS="$(VO_AACENC_CFLAGS)"
+
 $(eval $(autotools-package))