diff --git a/doc/jemalloc.xml.in b/doc/jemalloc.xml.in
index 8837d343..596f6458 100644
--- a/doc/jemalloc.xml.in
+++ b/doc/jemalloc.xml.in
@@ -358,7 +358,7 @@ for (i = 0; i < nbins; i++) {
             <listitem><para>Initialize newly allocated memory to contain zero
             bytes.  In the growing reallocation case, the real size prior to
             reallocation defines the boundary between untouched bytes and those
-            that are initialized to contain zero bytes.  If this option is
+            that are initialized to contain zero bytes.  If this macro is
             absent, newly allocated memory is uninitialized.</para></listitem>
           </varlistentry>
           <varlistentry>
@@ -373,9 +373,11 @@ for (i = 0; i < nbins; i++) {
             </constant></term>
 
             <listitem><para>Use the arena specified by the index
-            <parameter>a</parameter>.  This macro does not validate that
-            <parameter>a</parameter> specifies an arena in the valid
-            range.</para></listitem>
+            <parameter>a</parameter> (and by necessity bypass the thread
+            cache).  This macro has no effect for huge regions, nor for regions
+            that were allocated via an arena other than the one specified.
+            This macro does not validate that <parameter>a</parameter>
+            specifies an arena index in the valid range.</para></listitem>
           </varlistentry>
         </variablelist>
       </para>
diff --git a/src/jemalloc.c b/src/jemalloc.c
index 972f4546..491ec324 100644
--- a/src/jemalloc.c
+++ b/src/jemalloc.c
@@ -1530,7 +1530,7 @@ je_rallocm(void **ptr, size_t *rsize, size_t size, size_t extra, int flags)
 
 	if (arena_ind != UINT_MAX) {
 		arena_chunk_t *chunk;
-		try_tcache_alloc = true;
+		try_tcache_alloc = false;
 		chunk = (arena_chunk_t *)CHUNK_ADDR2BASE(*ptr);
 		try_tcache_dalloc = (chunk == *ptr || chunk->arena !=
 		    arenas[arena_ind]);