diff --git a/CHANGES b/CHANGES
index 983a9ae2ff..f5fa916cec 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,6 @@
+3866.	[bug]		Named could die on disk full in generate_session_key.
+			[RT #36119]
+
 3865.	[test]		Improved testability of the red-black tree
 			implementation and added unit tests. [RT #35904]
 
diff --git a/bin/named/server.c b/bin/named/server.c
index 3c62b9b1aa..789ca8a1ca 100644
--- a/bin/named/server.c
+++ b/bin/named/server.c
@@ -5097,8 +5097,8 @@ generate_session_key(const char *filename, const char *keynamestr,
 		(int) isc_buffer_usedlength(&key_txtbuffer),
 		(char*) isc_buffer_base(&key_txtbuffer));
 
-	RUNTIME_CHECK(isc_stdio_flush(fp) == ISC_R_SUCCESS);
-	RUNTIME_CHECK(isc_stdio_close(fp) == ISC_R_SUCCESS);
+	CHECK(isc_stdio_flush(fp));
+	CHECK(isc_stdio_close(fp));
 
 	dst_key_free(&key);
 
@@ -5111,6 +5111,11 @@ generate_session_key(const char *filename, const char *keynamestr,
 		      NS_LOGMODULE_SERVER, ISC_LOG_ERROR,
 		      "failed to generate session key "
 		      "for dynamic DNS: %s", isc_result_totext(result));
+	if (fp != NULL) {
+		if (isc_file_exists(filename))
+			(void)isc_file_remove(filename);
+		(void)isc_stdio_close(fp);
+	}
 	if (tsigkey != NULL)
 		dns_tsigkey_detach(&tsigkey);
 	if (key != NULL)