2 files changed, 4 insertions, 4 deletions

diff --git a/archival/gunzip.c b/archival/gunzip.c
index c3960e953..65f435651 100644
--- a/archival/gunzip.c
+++ b/archival/gunzip.c
@@ -158,9 +158,9 @@ extern int gunzip_main(int argc, char **argv)
 
                 delete_old_file = TRUE;
                 extension = strrchr(if_name, '.');
-                if (strcmp(extension, ".gz") == 0) {
+                if (extension && strcmp(extension, ".gz") == 0) {
                         length -= 3;
-                } else if (strcmp(extension, ".tgz") == 0) {
+                } else if (extension && strcmp(extension, ".tgz") == 0) {
                         length -= 4;
                 } else {
                         error_msg_and_die("Invalid extension");
diff --git a/gunzip.c b/gunzip.c
index c3960e953..65f435651 100644
--- a/gunzip.c
+++ b/gunzip.c
@@ -158,9 +158,9 @@ extern int gunzip_main(int argc, char **argv)
 
                 delete_old_file = TRUE;
                 extension = strrchr(if_name, '.');
-                if (strcmp(extension, ".gz") == 0) {
+                if (extension && strcmp(extension, ".gz") == 0) {
                         length -= 3;
-                } else if (strcmp(extension, ".tgz") == 0) {
+                } else if (extension && strcmp(extension, ".tgz") == 0) {
                         length -= 4;
                 } else {
                         error_msg_and_die("Invalid extension");