diff --git a/src/yajl/yajl_gen.c b/src/yajl/yajl_gen.c
index 7c06a32..1f0ab44 100644
--- a/src/yajl/yajl_gen.c
+++ b/src/yajl/yajl_gen.c
@@ -182,10 +182,16 @@ yajl_gen_free(yajl_gen g)
     }
 
 #define INCREMENT_DEPTH \
-    if (++(g->depth) >= YAJL_MAX_DEPTH) return yajl_max_depth_exceeded;
+    do { \
+        if (g->depth >= YAJL_MAX_DEPTH - 1) return yajl_max_depth_exceeded; \
+        g->depth++; \
+    } while (0)
 
 #define DECREMENT_DEPTH \
-  if (--(g->depth) >= YAJL_MAX_DEPTH) return yajl_gen_generation_complete;
+    do { \
+        if (g->depth == 0) return yajl_gen_generation_complete; \
+        g->depth--; \
+    } while (0)
 
 #define APPENDED_ATOM \
     switch (g->state[g->depth]) {                   \
diff --git a/tests/testthat/test-prettify.R b/tests/testthat/test-prettify.R
new file mode 100644
index 0000000..edee1aa
--- /dev/null
+++ b/tests/testthat/test-prettify.R
@@ -0,0 +1,25 @@
+# test case from https://github.com/lloyd/yajl/issues/204
+test_that("depth limit is enforced to avoid out-of-bounds", {
+  # Deep nesting limit checks
+  deep_array <- strrep("[", 130L)
+  expect_error(minify(deep_array), "client cancelled parse")
+  expect_error(prettify(deep_array), "client cancelled parse")
+  
+  err_str <- "[[{} ,[[[{} ,[{} ,[[],[[[9],[9],[],[[[9],[[[[],[[9],[9],[[9],[[[[],[[9],[[[9],[[],[[[[],[[9 ,[{} ,[[],[[[9],[9],[],[[[9],[[[[[9],[[[[],[[9],[9],[7],[],[[[9],[[[[[9],[[[[],[[9],[[[9],[[],[[[[],[[9],[9],[],[[[9],[[[[[9],[[[[],[[],[[9],[[[[],[[9],[[],[],[]],[[]],[],[],[[9],[[],[],[[],[[],9],[],[[[9],[[[[[9],[],[9],[],[[[9],[[[[[9],[[[[],[[9],[[[[],[[9],[[],[],[]],[[],[[9],[[9],[9],[],[[[9],[[[[[9],[[[[],[[9],[[[[],[[9],[[],[],[]],[[]],[],[],[[9],[[],[],[[],[[],[[[9],[9],[],[[[9],[9],[[[[],[[9],[[[[],[[9],[[],[],[]],[[[9],[9],[[[[],[[9],[[[[],[[9],[[],[],[]],[[]]C[],[],[[9],[[],[],[[],[[],[[[9],[9],[],[[[9],[[],[[[[],[[9],[[[[["
+  expect_error(minify(err_str), "client cancelled parse")
+  expect_error(prettify(err_str), "client cancelled parse")
+})
+
+# test case from https://github.com/lloyd/yajl/issues/205
+test_that("no invalid read on deep array with unclosed string", {
+  err_str <- '{"[9[":[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[4[[[[[[[[[[[[[[[[[[[[[[[[H[[[[[[[[[[K[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[{[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[E[[[[[[[[[[[[[[j[[[[[[[[[[[[[][[[[[[[[[[[[[[[[[[":[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[g[@[[[[[[[[[[[[[[[[\\M[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[k[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[\n'
+  expect_error(minify(err_str), "client cancelled parse")
+  expect_error(prettify(err_str), "client cancelled parse")
+})
+
+# test case from https://github.com/lloyd/yajl/issues/206
+test_that("no uninitialised read on malformed deep array", {
+  err_str <- '[[[[[{"ARY":[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[[],{"AR":[{"URY":[[[],\t"",{" R":[\t"",{" R":{" R":[\t"",{" R":[[],{"AR":{" ;":[[[[],{"AR":[{"URY":[[],[[[9],[],\t"",{" R":[\t"",{" R":["",{" R":[\t"",{" R":[[],{"AR R":[[],{" URY":[[[9],[:[\x16"",{" R":["",{" R":[\t"",{" R"D[[],{"AR":[[],{"AR":[{"URAR":{" R":[[],\t"",[],{"AR":[ ,[{"Y":[[],{"AR":[{"URY":[[],[\t"",{" R":[\t"",{" [[[[[],{" R":[\t"",{" R" [[],{"RY":[[],{"AR":[{"URY":[[],[[[9],[],\t"",{" R":[\t"",{" R":["",{" R":[\t"",{" R":[[],{"AR":{" R":[[],{" URY":[[],[[[9],[],{" R":[\t""{"[\t\n'
+  expect_error(minify(err_str), "client cancelled parse")
+  expect_error(prettify(err_str), "client cancelled parse")
+})