diff --git a/src/pj_param.c b/src/pj_param.c
index 6cee4d1fba..7ed0e37716 100644
--- a/src/pj_param.c
+++ b/src/pj_param.c
@@ -42,7 +42,7 @@ paralist *pj_mkparam_ws (char *str) {
     }
 
     /* Use calloc to automagically 0-terminate the copy */
-    newitem = (paralist *) pj_calloc (1, sizeof(paralist) + len);
+    newitem = (paralist *) pj_calloc (1, sizeof(paralist) + len + 1);
     if (0==newitem)
         return 0;
     memmove(newitem->param, str, len);
diff --git a/src/projects.h b/src/projects.h
index 2dc073fa73..928985f65a 100644
--- a/src/projects.h
+++ b/src/projects.h
@@ -458,7 +458,12 @@ struct PJconsts {
 struct ARG_list {
     paralist *next;
     char used;
-    char param[1];
+#ifdef __GNUC__
+    char param[0]; /* variable-length member */
+    /* Safer to use [0] for gcc. See /~https://github.com/OSGeo/proj.4/pull/1087 */
+#else
+    char param[1]; /* variable-length member */
+#endif
 };