diff --git a/src/algs/cdirect/cdirect.c b/src/algs/cdirect/cdirect.c
index 1cfd78f0..dbb1f2a8 100644
--- a/src/algs/cdirect/cdirect.c
+++ b/src/algs/cdirect/cdirect.c
@@ -579,7 +579,7 @@ nlopt_result cdirect(int n, nlopt_func f, void *f_data,
      int i;
 
      d.f = f; d.f_data = f_data; d.lb = lb; d.ub = ub;
-     d.x = (double *) malloc(sizeof(double) * n * (stop->xtol_abs ? 4 : 3));
+     d.x = (double *) calloc(n * (stop->xtol_abs ? 4 : 3), sizeof(double));
      if (!d.x) return NLOPT_OUT_OF_MEMORY;
      
      for (i = 0; i < n; ++i) {
diff --git a/src/algs/cdirect/hybrid.c b/src/algs/cdirect/hybrid.c
index 4ddb5a08..4af08d4f 100644
--- a/src/algs/cdirect/hybrid.c
+++ b/src/algs/cdirect/hybrid.c
@@ -320,7 +320,7 @@ nlopt_result cdirect_hybrid(int n, nlopt_func f, void *f_data,
      int i;
 
      d.f = f; d.f_data = f_data; d.lb = lb; d.ub = ub;
-     d.x = (double *) malloc(sizeof(double) * n * (stop->xtol_abs ? 4 : 3));
+     d.x = (double *) calloc(n * (stop->xtol_abs ? 4 : 3), sizeof(double));
      if (!d.x) return NLOPT_OUT_OF_MEMORY;
 
      for (i = 0; i < n; ++i) {