@@ -128,10 +128,14 @@
 	Tcl_Obj **objv;
 	const char *arg;
 	va_list argp;
 	int retval;
 	int i;
+
+	if (interp == NULL) {
+		return(TCL_ERROR);
+	}
 
 	objv = (void *) ckalloc(sizeof(*objv) * objc);
 	objv[0] = Tcl_NewStringObj(cmd, -1);
 	Tcl_IncrRefCount(objv[0]);
 
@@ -165,10 +169,14 @@
 	APPFS_DEBUG("Enter: hostname = %s", hostname);
 
 	interp = pthread_getspecific(interpKey);
 	if (interp == NULL) {
 		interp = appfs_create_TclInterp(globalThread.cachedir);
+
+		if (interp == NULL) {
+			return;
+		}
 
 		pthread_setspecific(interpKey, interp);
 	}
 
 	tcl_ret = appfs_Tcl_Eval(interp, 2, "::appfs::getindex", hostname);
@@ -187,10 +195,14 @@
 	int tcl_ret;
 
 	interp = pthread_getspecific(interpKey);
 	if (interp == NULL) {
 		interp = appfs_create_TclInterp(globalThread.cachedir);
+
+		if (interp == NULL) {
+			return(NULL);
+		}
 
 		pthread_setspecific(interpKey, interp);
 	}
 
 	tcl_ret = appfs_Tcl_Eval(interp, 3, "::appfs::download", hostname, sha1);
@@ -210,10 +222,14 @@
 	int tcl_ret;
 
 	interp = pthread_getspecific(interpKey);
 	if (interp == NULL) {
 		interp = appfs_create_TclInterp(globalThread.cachedir);
+
+		if (interp == NULL) {
+			return;
+		}
 
 		pthread_setspecific(interpKey, interp);
 	}
 
 	tcl_ret = appfs_Tcl_Eval(interp, 3, "::appfs::getpkgmanifest", hostname, sha1);