diff --git a/eigerApp/src/eigerDetector.cpp b/eigerApp/src/eigerDetector.cpp
index c5d1bdd..e157edb 100644
--- a/eigerApp/src/eigerDetector.cpp
+++ b/eigerApp/src/eigerDetector.cpp
@@ -725,7 +725,14 @@ asynStatus eigerDetector::writeOctet (asynUser *pasynUser, const char *value,
         if(!strlen(value))
         {
             mFsGid = getgid();
-            mFileOwnerGroup->put(getgrgid(mFsGid)->gr_name);
+	    struct group* pgroup = getgrgid(mFsGid);
+
+	    if (pgroup) {
+		mFileOwnerGroup->put(pgroup->gr_name);
+	    } else {
+                ERR("couldn't find gid");
+                status = asynError;
+	    }
         }
         else
         {