diff --git a/src/rp2_common/boot_stage2/CMakeLists.txt b/src/rp2_common/boot_stage2/CMakeLists.txt
index 71fbabe..a2f3960 100644
--- a/src/rp2_common/boot_stage2/CMakeLists.txt
+++ b/src/rp2_common/boot_stage2/CMakeLists.txt
@@ -4,7 +4,7 @@
 if (DEFINED ENV{PICO_DEFAULT_BOOT_STAGE2_FILE})
     set(PICO_DEFAULT_BOOT_STAGE2_FILE $ENV{PICO_DEFAULT_BOOT_STAGE2_FILE})
     message("Using PICO_DEFAULT_BOOT_STAGE2_FILE from environment ('${PICO_DEFAULT_BOOT_STAGE2_FILE}')")
-elif (PICO_DEFAULT_BOOT_STAGE2_FILE)
+elseif (PICO_DEFAULT_BOOT_STAGE2_FILE)
     # explicitly set, so cache it
     set(PICO_DEFAULT_BOOT_STAGE2_FILE "${PICO_DEFAULT_BOOT_STAGE2_FILE}" CACHE STRING "boot stage 2 source file" FORCE)
 endif()