diff --git a/rules.mk b/rules.mk
index 53d4468dfc4bab6c1a3455e10e0281c70559b5bc..6455fde3f147108044bcf081ba374dd62267940a 100644
--- a/rules.mk
+++ b/rules.mk
@@ -60,7 +60,7 @@ ifneq ($(filter -march=armv%,$(TARGET_OPTIMIZATION)),)
   ARCH_SUFFIX:=_$(patsubst -march=arm%,%,$(filter -march=armv%,$(TARGET_OPTIMIZATION)))
   GCC_ARCH:=$(patsubst -march=%,%,$(filter -march=armv%,$(TARGET_OPTIMIZATION)))
 endif
-ifneq ($(findstring -mips32r2,$(TARGET_OPTIMIZATION)),)
+ifneq ($(filter -mips%r2,$(TARGET_OPTIMIZATION)),)
   ARCH_SUFFIX:=_r2
 endif
 ifdef CONFIG_HAS_SPE_FPU