diff --git a/libgfortran/ChangeLog b/libgfortran/ChangeLog
index 00e65ab72f91..6c253b0d0ccd 100644
--- a/libgfortran/ChangeLog
+++ b/libgfortran/ChangeLog
@@ -1,3 +1,8 @@
+2011-11-11  Janne Blomqvist  <jb@gcc.gnu.org>
+
+	PR libfortran/51090
+	* runtime/main.c (find_addr2line): NULL check before proceeding.
+
 2011-11-10  Janne Blomqvist  <jb@gcc.gnu.org>
 
 	* intrinsics/cpu_time.c (__cpu_time_1): Don't force inlining.
diff --git a/libgfortran/runtime/main.c b/libgfortran/runtime/main.c
index bc8dab449e8f..6ce5388c6f46 100644
--- a/libgfortran/runtime/main.c
+++ b/libgfortran/runtime/main.c
@@ -149,6 +149,8 @@ find_addr2line (void)
 #ifdef HAVE_ACCESS
 #define A2L_LEN 10
   char *path = getenv ("PATH");
+  if (!path)
+      return;
   size_t n = strlen (path);
   char ap[n + 1 + A2L_LEN];
   size_t ai = 0;