diff --git a/tests/fp/Makefile b/tests/fp/Makefile
index d649a5a1db42239bb20518f218662f7bdb8f65cd..49cdcd1bd29fdbf846e0c8149c65383619bb9924 100644
--- a/tests/fp/Makefile
+++ b/tests/fp/Makefile
@@ -29,6 +29,9 @@ QEMU_INCLUDES += -I$(TF_SOURCE_DIR)
 
 # work around TARGET_* poisoning
 QEMU_CFLAGS += -DHW_POISON_H
+# define a target to match testfloat's implementation-defined choices, such as
+# whether to raise the invalid flag when dealing with NaNs in muladd.
+QEMU_CFLAGS += -DTARGET_ARM
 
 # capstone has a platform.h file that clashes with softfloat's
 QEMU_CFLAGS := $(filter-out %capstone, $(QEMU_CFLAGS))