diff --git a/src/H5FDmpio.c b/src/H5FDmpio.c
index 7141550f40a..83a5ad45a9a 100644
--- a/src/H5FDmpio.c
+++ b/src/H5FDmpio.c
@@ -906,7 +906,7 @@ H5FD__mpio_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t H5_ATTR
 
             /* copy over each hint */
             for (i = 0; i < nkeys; i++) {
-                char key[MPI_MAX_INFO_KEY], value[MPI_MAX_INFO_VAL];
+                char key[MPI_MAX_INFO_KEY], value[MPI_MAX_INFO_VAL + 1];
                 int  valuelen, flag;
 
                 /* retrieve the nth hint */
@@ -916,7 +916,7 @@ H5FD__mpio_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t H5_ATTR
                 if (MPI_SUCCESS != (mpi_code = MPI_Info_get_valuelen(info_used, key, &valuelen, &flag)))
                     HMPI_GOTO_ERROR(NULL, "MPI_Info_get_valuelen failed", mpi_code)
                 /* retrieve the value of nth hint */
-                if (MPI_SUCCESS != (mpi_code = MPI_Info_get(info_used, key, valuelen + 1, value, &flag)))
+                if (MPI_SUCCESS != (mpi_code = MPI_Info_get(info_used, key, valuelen, value, &flag)))
                     HMPI_GOTO_ERROR(NULL, "MPI_Info_get failed", mpi_code)
 
                 /* copy the hint into info */
diff --git a/src/H5mpi.c b/src/H5mpi.c
index 2725ec5bf19..cf7e33d46c9 100644
--- a/src/H5mpi.c
+++ b/src/H5mpi.c
@@ -380,9 +380,9 @@ H5_mpi_info_cmp(MPI_Info info1, MPI_Info info2, int *result)
             /* Allocate buffers for iteration */
             if (NULL == (key = (char *)H5MM_malloc(MPI_MAX_INFO_KEY * sizeof(char))))
                 HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
-            if (NULL == (value1 = (char *)H5MM_malloc(MPI_MAX_INFO_VAL * sizeof(char))))
+            if (NULL == (value1 = (char *)H5MM_malloc((MPI_MAX_INFO_VAL + 1) * sizeof(char))))
                 HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
-            if (NULL == (value2 = (char *)H5MM_malloc(MPI_MAX_INFO_VAL * sizeof(char))))
+            if (NULL == (value2 = (char *)H5MM_malloc((MPI_MAX_INFO_VAL + 1) * sizeof(char))))
                 HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed");
 
             /* Iterate over the keys, comparing them */