diff --git a/boot/zephyr/include/target.h b/boot/zephyr/include/target.h
index de9ecaf..d37a523 100644
--- a/boot/zephyr/include/target.h
+++ b/boot/zephyr/include/target.h
@@ -9,8 +9,6 @@
 /* Board-specific definitions go first, to allow maximum override. */
 #if defined(MCUBOOT_TARGET_CONFIG)
 #include MCUBOOT_TARGET_CONFIG
-#else
-#error "Board is currently not supported by bootloader"
 #endif
 
 /* SoC family configuration. */
@@ -18,4 +16,20 @@
 #include "soc_family_nrf5.h"
 #endif
 
+/*
+ * This information can come from DTS, a target-specific header file,
+ * or an SoC-specific header file. If any of it is missing, target
+ * support is incomplete.
+ */
+#if !defined(FLASH_DRIVER_NAME) || \
+    !defined(FLASH_ALIGN) ||                  \
+    !defined(FLASH_AREA_IMAGE_0_OFFSET) || \
+    !defined(FLASH_AREA_IMAGE_0_SIZE) || \
+    !defined(FLASH_AREA_IMAGE_1_OFFSET) || \
+    !defined(FLASH_AREA_IMAGE_1_SIZE) || \
+    !defined(FLASH_AREA_IMAGE_SCRATCH_OFFSET) || \
+    !defined(FLASH_AREA_IMAGE_SCRATCH_SIZE)
+#error "Target support is incomplete; cannot build mcuboot."
+#endif
+
 #endif