diff --git a/.gitignore b/.gitignore
index 66f233f..a9d7413 100644
--- a/.gitignore
+++ b/.gitignore
@@ -14,6 +14,10 @@
 /dhrystone/timing.txt
 /dhrystone/*.d
 /dhrystone/*.o
+/riscv-gnu-toolchain-riscv32i
+/riscv-gnu-toolchain-riscv32ic
+/riscv-gnu-toolchain-riscv32im
+/riscv-gnu-toolchain-riscv32imc
 /testbench.exe
 /testbench_sp.exe
 /testbench_axi.exe
diff --git a/Makefile b/Makefile
index 0fa3583..5948bd5 100644
--- a/Makefile
+++ b/Makefile
@@ -103,6 +103,8 @@ toc:
 	gawk '/^-+$$/ { y=tolower(x); gsub("[^a-z0-9]+", "-", y); gsub("-$$", "", y); printf("- [%s](#%s)\n", x, y); } { x=$$0; }' README.md
 
 clean:
+	rm -rf riscv-gnu-toolchain-riscv32i riscv-gnu-toolchain-riscv32ic \
+		riscv-gnu-toolchain-riscv32im riscv-gnu-toolchain-riscv32imc
 	rm -vrf $(FIRMWARE_OBJS) $(TEST_OBJS) check.smt2 check.vcd synth.v synth.log \
 		firmware/firmware.elf firmware/firmware.bin firmware/firmware.hex firmware/firmware.map \
 		testbench.exe testbench_sp.exe testbench_synth.exe testbench.vcd