diff --git a/CI/build/arduino-cli.py b/CI/build/arduino-cli.py
index 3b013b7e1d..d4ec5797bc 100644
--- a/CI/build/arduino-cli.py
+++ b/CI/build/arduino-cli.py
@@ -91,7 +91,7 @@
 # error or fatal error
 fork_pattern = re.compile(r"^Error during build: fork/exec")
 error_pattern = re.compile(r":\d+:\d*:?\s.*error:\s|^Error:|fatal error:")
-ld_pattern = re.compile("arm-none-eabi/bin/ld\.?e?x?e?:")
+ld_pattern = re.compile(r"arm-none-eabi/bin/ld\.?e?x?e?:")
 overflow_pattern = re.compile(
     r"(will not fit in |section .+ is not within )?region( .+ overflowed by [\d]+ bytes)?"
 )