diff --git a/test/box/gh-3633-tuple-size-increasing.result b/test/box/gh-3633-tuple-size-increasing.result
index c9a51b4d35083113878011f9f3431f1e0b168036..934849be88119eb152e3f084868aaa570df58278 100644
--- a/test/box/gh-3633-tuple-size-increasing.result
+++ b/test/box/gh-3633-tuple-size-increasing.result
@@ -47,7 +47,7 @@ str = digest.urandom(size)
  | ---
  | ...
 -- insert tuples, until we get error due to no enough of memory
-for i = 1, 1024 do s:insert({i, str}) end
+for i = 1, 1049 do s:insert({i, str}) end
  | ---
  | - error: Failed to allocate 512019 bytes in slab allocator for memtx_tuple
  | ...
diff --git a/test/box/gh-3633-tuple-size-increasing.test.lua b/test/box/gh-3633-tuple-size-increasing.test.lua
index adad7169fcbc6fcc9a8f9e4e5926dd7aaee9da2a..7f6069fa18f9edcc8b0cccd708d065109556a6da 100644
--- a/test/box/gh-3633-tuple-size-increasing.test.lua
+++ b/test/box/gh-3633-tuple-size-increasing.test.lua
@@ -17,7 +17,7 @@ test_run:cmd("setopt delimiter ''");
 size = 500 * 1024
 str = digest.urandom(size)
 -- insert tuples, until we get error due to no enough of memory
-for i = 1, 1024 do s:insert({i, str}) end
+for i = 1, 1049 do s:insert({i, str}) end
 -- truncate space, and collect garbage (free previous allocated memory)
 s:truncate()
 collectgarbage('collect')
diff --git a/test/box/reconfigure.result b/test/box/reconfigure.result
index 021ed8fc0f4fc3448645a2c91729fb99db2aaa45..3a1b86700cbf9017adf6a9210d33c5410282a3bd 100644
--- a/test/box/reconfigure.result
+++ b/test/box/reconfigure.result
@@ -148,15 +148,15 @@ s = box.schema.space.create('test')
 _ = s:create_index('pk')
 ---
 ...
-count = 200
+count = 1000
 ---
 ...
 pad = string.rep('x', 100 * 1024)
 ---
 ...
-for i = 1, count do s:replace{i, pad} end -- error: not enough memory
+for i = 1, count do s:replace{i + 1000, pad} end -- error: not enough memory
 ---
-- error: Failed to allocate 102418 bytes in slab allocator for memtx_tuple
+- error: Failed to allocate 102419 bytes in slab allocator for memtx_tuple
 ...
 s:count() < count
 ---
@@ -169,7 +169,10 @@ box.slab.info().quota_size
 ---
 - 83886080
 ...
-for i = s:count() + 1, count do s:replace{i, pad} end -- ok
+count = s:count() + 100
+---
+...
+for i = s:count() + 1, count do s:replace{i + 1000, pad} end -- ok
 ---
 ...
 s:count() == count
diff --git a/test/box/reconfigure.test.lua b/test/box/reconfigure.test.lua
index 40fbecf8fbe0ed989bd4a3114dbc00ec8d2351a5..a82cfa02399d1d8cfb4d8dbb0768ff044e8d5d60 100644
--- a/test/box/reconfigure.test.lua
+++ b/test/box/reconfigure.test.lua
@@ -61,15 +61,16 @@ box.slab.info().quota_size
 
 s = box.schema.space.create('test')
 _ = s:create_index('pk')
-count = 200
+count = 1000
 pad = string.rep('x', 100 * 1024)
-for i = 1, count do s:replace{i, pad} end -- error: not enough memory
+for i = 1, count do s:replace{i + 1000, pad} end -- error: not enough memory
 s:count() < count
 
 box.cfg{memtx_memory = 80 * 1024 * 1024}
 box.slab.info().quota_size
 
-for i = s:count() + 1, count do s:replace{i, pad} end -- ok
+count = s:count() + 100
+for i = s:count() + 1, count do s:replace{i + 1000, pad} end -- ok
 s:count() == count
 s:drop()
 
diff --git a/test/wal_off/oom.result b/test/wal_off/oom.result
index 623809fb2e5f09dd23494c83b9e04ef648c4b793..539f8ec975ade752c125ca7cf90a22e6567a833c 100644
--- a/test/wal_off/oom.result
+++ b/test/wal_off/oom.result
@@ -252,7 +252,7 @@ collectgarbage('collect')
 ---
 - 0
 ...
-for i=1,10000 do space:insert{i, str} end
+for i=1,10492 do space:insert{i, str} end
 ---
 - error: Failed to allocate <NUM> bytes in slab allocator for memtx_tuple
 ...
@@ -277,7 +277,7 @@ collectgarbage('collect')
 ---
 - 0
 ...
-for i=1,10000 do space:insert{i, str} end
+for i=1,10492 do space:insert{i, str} end
 ---
 - error: Failed to allocate <NUM> bytes in slab allocator for memtx_tuple
 ...
diff --git a/test/wal_off/oom.test.lua b/test/wal_off/oom.test.lua
index 6b3cf2c65a0f1bab07a6fc16e916b7e90231d272..3c1b897d2b2b4ca9eacfbe1e842dde278f3f5f9c 100644
--- a/test/wal_off/oom.test.lua
+++ b/test/wal_off/oom.test.lua
@@ -91,7 +91,7 @@ space = box.schema.space.create('tweedledum')
 index = space:create_index('primary', { type = 'hash' })
 
 collectgarbage('collect')
-for i=1,10000 do space:insert{i, str} end
+for i=1,10492 do space:insert{i, str} end
 definitely_used = index:count() * 16 * 1024
 2 * definitely_used > arena_bytes -- at least half memory used
 to_del = index:count()
@@ -99,7 +99,7 @@ for i=1,to_del do space:delete{i} end
 index:count()
 
 collectgarbage('collect')
-for i=1,10000 do space:insert{i, str} end
+for i=1,10492 do space:insert{i, str} end
 definitely_used = index:count() * 16 * 1024
 2 * definitely_used > arena_bytes -- at least half memory used
 space:truncate()