diff --git a/library/Makefile b/library/Makefile
index 2f42124..77cfe07 100644
--- a/library/Makefile
+++ b/library/Makefile
@@ -2,15 +2,25 @@
 MBEDTLS_PATH := ..
 endif
 
-ifeq (,$(wildcard $(MBEDTLS_PATH)/framework/exported.make))
-define error_message
+GENERATED_FILES := \
+	error.c version_features.c \
+	ssl_debug_helpers_generated.c \
+	psa_crypto_driver_wrappers.h \
+	psa_crypto_driver_wrappers_no_static.c
+
+ifneq ($(GENERATED_FILES),$(wildcard $(GENERATED_FILES)))
+    ifeq (,$(wildcard $(MBEDTLS_PATH)/framework/exported.make))
+        # Use the define keyword to get a multi-line message.
+        # GNU make appends ".  Stop.", so tweak the ending of our message accordingly.
+        define error_message
 $(MBEDTLS_PATH)/framework/exported.make not found.
 Run `git submodule update --init` to fetch the submodule contents.
 This is a fatal error
-endef
-$(error $(error_message))
+        endef
+        $(error $(error_message))
+    endif
+    include $(MBEDTLS_PATH)/framework/exported.make
 endif
-include $(MBEDTLS_PATH)/framework/exported.make
 
 # Also see "include/mbedtls/mbedtls_config.h"
 
@@ -327,11 +337,6 @@
 	$(CC) $(LOCAL_CFLAGS) $(CFLAGS) -o $@ -c $<
 
 .PHONY: generated_files
-GENERATED_FILES = \
-	error.c version_features.c \
-	ssl_debug_helpers_generated.c \
-	psa_crypto_driver_wrappers.h \
-	psa_crypto_driver_wrappers_no_static.c
 generated_files: $(GENERATED_FILES)
 
 # See root Makefile