diff --git a/compiler/ccgexprs.nim b/compiler/ccgexprs.nim
index 95167e1576..691feeb472 100644
--- a/compiler/ccgexprs.nim
+++ b/compiler/ccgexprs.nim
@@ -1578,15 +1578,15 @@ proc genMagicExpr(p: BProc, e: PNode, d: var TLoc, op: TMagic) =
   of mGetTypeInfo: genGetTypeInfo(p, e, d)
   of mSwap: genSwap(p, e, d)
   of mUnaryLt: 
-    if not (optOverflowCheck in p.options): unaryExpr(p, e, d, "$1 - 1")
+    if not (optOverflowCheck in p.options): unaryExpr(p, e, d, "($1 - 1)")
     else: unaryExpr(p, e, d, "#subInt($1, 1)")
   of mPred:
     # XXX: range checking?
-    if not (optOverflowCheck in p.options): binaryExpr(p, e, d, "$1 - $2")
+    if not (optOverflowCheck in p.options): binaryExpr(p, e, d, "($1 - $2)")
     else: binaryExpr(p, e, d, "#subInt($1, $2)")
   of mSucc:
     # XXX: range checking?
-    if not (optOverflowCheck in p.options): binaryExpr(p, e, d, "$1 + $2")
+    if not (optOverflowCheck in p.options): binaryExpr(p, e, d, "($1 + $2)")
     else: binaryExpr(p, e, d, "#addInt($1, $2)")
   of mInc:
     if not (optOverflowCheck in p.options):
diff --git a/lib/pure/collections/tables.nim b/lib/pure/collections/tables.nim
index ce9df09e10..dcf2ab4811 100644
--- a/lib/pure/collections/tables.nim
+++ b/lib/pure/collections/tables.nim
@@ -246,7 +246,8 @@ template equalsImpl() =
     # different insertion orders mean different 'data' seqs, so we have
     # to use the slow route here:
     for key, val in s:
-      if not hasKey(t, key): return false
+      # prefix notation leads to automatic dereference in case of PTable
+      if not t.hasKey(key): return false
       if t[key] != val: return false
     return true
   
@@ -332,7 +333,9 @@ proc `$`*[A, B](t: PTable[A, B]): string =
   dollarImpl()
 
 proc `==`*[A, B](s, t: PTable[A, B]): bool =
-  equalsImpl()
+  if isNil(s): result = isNil(t)
+  elif isNil(t): result = false
+  else: result = equalsImpl()
 
 proc newTableFrom*[A, B, C](collection: A, index: proc(x: B): C): PTable[C, B] =
   ## Index the collection with the proc provided.
diff --git a/lib/pure/json.nim b/lib/pure/json.nim
index 508e564c57..a45900f297 100644
--- a/lib/pure/json.nim
+++ b/lib/pure/json.nim
@@ -621,9 +621,13 @@ proc `%`*(elements: openArray[PJsonNode]): PJsonNode =
 
 proc `==`* (a,b: PJsonNode): bool =
   ## Check two nodes for equality
-  if a.kind != b.kind: false
+  if a.isNil:
+    if b.isNil: return true
+    return false
+  elif b.isNil or a.kind != b.kind: 
+    return false
   else:
-    case a.kind
+    return case a.kind
     of JString:
       a.str == b.str
     of JInt:
diff --git a/lib/pure/osproc.nim b/lib/pure/osproc.nim
index 04a0c2403a..c74fa1ceb6 100644
--- a/lib/pure/osproc.nim
+++ b/lib/pure/osproc.nim
@@ -763,7 +763,7 @@ elif not defined(useNimRtl):
     discard write(data.pErrorPipe[writeIdx], addr error, sizeof(error))
     exitnow(1)
 
-  when defined(macosx):
+  when defined(macosx) or defined(freebsd):
     var environ {.importc.}: cstringArray
 
   proc startProcessAfterFork(data: ptr TStartProcessData) =
@@ -793,7 +793,7 @@ elif not defined(useNimRtl):
     discard fcntl(data.pErrorPipe[writeIdx], F_SETFD, FD_CLOEXEC)
 
     if data.optionPoUsePath:
-      when defined(macosx):
+      when defined(macosx) or defined(freebsd):
         # MacOSX doesn't have execvpe, so we need workaround.
         # On MacOSX we can arrive here only from fork, so this is safe:
         environ = data.sysEnv
diff --git a/tests/table/ptables.nim b/tests/table/ptables.nim
index ec52d08c33..79a9aab171 100644
--- a/tests/table/ptables.nim
+++ b/tests/table/ptables.nim
@@ -104,6 +104,15 @@ block countTableTest1:
 block SyntaxTest:
   var x = newTable[int, string]({:})
 
+block nilTest:
+  var i, j: PTable[int, int] = nil
+  assert i == j
+  j = newTable[int, int]()
+  assert i != j
+  assert j != i
+  i = newTable[int, int]()
+  assert i == j
+
 proc orderedTableSortTest() =
   var t = newOrderedTable[string, int](2)
   for key, val in items(data): t[key] = val